When comparing Sketch vs Blender, the Slant community recommends Sketch for most people. In the question“What are the best graphic design programs?” Sketch is ranked 4th while Blender is ranked 7th. The most important reason people chose Sketch is:
Sketch is essentially a version of Photoshop built from the ground up to suit the workflow of web designers.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Designed specifically for web and mobile UI design & workflows
Sketch is essentially a version of Photoshop built from the ground up to suit the workflow of web designers.
Pro Active community with a lot of resources
Sketch is hugely popular among designers so there are a lot of well maintained community resources for everything from iPhone frames to iOS/Android UI elements & icons.
Pro Clean UI
Reactive panels keep the UI for Sketch clean from the sort of clutter the panel system in Photoshop suffers from. The panels in Sketch change based on the object in question, saving you from having to have a multiple separate panels.
Pro Symbols and shared styles
Sketch lets you re-use the same design in multiple places, with changes synced throughout the various places it is used. You can also create text styles to sync typography changes.
Pro "Artboards" are great for working on multiple views simultaneously
Artboards let you easily work on multiple views side by side. Great for having a separate artboard on each page for the various responsive sizes.
Pro Vector based yet pixel aware
You can rescale assets without quality loss, easily export x2 assets for retina designs and design high quality icons & artwork. Being pixel aware lets you set a grid and snap objects to it as well as round to the nearest pixel edge to clean up your layers.
Pro Makes it easy to export assets
Sketch has a built in exporter that supports PDF, JPG and PNG.
Pro Built-in grid system
You can set the square grid to whatever dimensions you like as well as set thicker lines every x blocks. You can also configure the color of the lines to make them as obvious or subtle as you wish and toggle the grid with a keyboard shortcut (crtl+g).
Pro "Mirror" makes it really easy to test designs on multiple devices
Mirror lets you connect your iPhone to sketch and see how your current artboard looks on mobile. It's really useful as you can live check changes which lets you rapidly iterate mobile design.
Pro Easily align layers with smart guides
Holding down alt will show the smart guides that show the distances between any layer you hover over to nearby layers or the edges of the artboard. Very useful for checking your spacing or aligning layers.


Pro Free and open source
Blender is licensed under the GPL. Some Blender modules such as the Cycles rendering engine are licensed under the Apache 2.0 license.

Pro Wide import and export format support
Support lots of modern 3D formats including DAE and FBX - ideal for game developers.
Pro Has a powerful rendering engine
Blender runs the Cycles path tracing engine under the hood. Cycles is a very powerful rendering engine capable of full path tracing (light fall off, caustics, volumetrics). It is mostly compatible with OpenCL and CUDA rendering, and is implementing mycropolygon displacement features. The upcoming release has a viewport engine called EEVEE whereby you can see and interact with your work in render mode in real time!

Pro Python extensibility
Blender embeds Python 3, which can be used to write add-ons, tools, extend the interface, rig characters and automate tasks.

Pro Powerful animation suite
Blender provides a full rigging system, and automates animation by interpolating between keyframe positions.
Pro Supports both low-poly and hi-poly modeling

Pro Regular release schedule
Releases are made every ~3 months.
Pro Sculpting and 3D painting features
Although Blender's 3d painting and sculpting tools (mostly painting) are not at par with specialized software like Substance Painter, ZBrush, or Mari, it is more than capable of getting most jobs done if the user takes the time to learn and understand it.

Pro Includes video editing & compositing tools
Blender's node-based compositor has comprehensive video sequencing and post-processing features.
Pro Node based modeling support
Pro Keyboard shortcuts
Good keyboard shortcuts for everything. Keep your left hand on the keyboard and your right hand on the mouse.
Pro Very useful for a freelancer
It offers a round solution (it covers many areas and professional fields) for a freelancer, for free, constantly updated, very polished, and allowing high quality results that clients do require. After some learning, it becomes very useful for professional work.
Pro Has a large community
There's a huge community to help you get started immediately.
Pro Coherent and streamlined workflow / internal use logic
The trick with Blender is to get used to its usage philosophy, as it keeps consistent through all the application. Once you get it, every feature or addition is learnt naturally, almost effortlessly.
Pro Very versatile
You don't have to switch between software when you want to do different things. Because modeling, sculpting, composting, video editing etc can all be done in blender.
Pro Generative geometry using nodes
Cons
Con No Windows support
Con No Linux version
Sketch is currently only available on Mac, which can make it hard to collaborate if you have teammates using Linux.
Con License based payment model
Sketch has recently decided to cease development of major version (2.0, 3.0, 4.0) with free updates in between, and has switched to a license based subscription model. A yearly license costs $99 and includes the latest version of the Sketch software, plus a year of free updates. After this license expires, you can renew for another year of updates - or continue to use the current software without updates.
Con Buggy releases and lack of quality assurance
The fast rate of change means new releases often break files and cause havoc. Duplicate symbols are really bad in the latest releases so you have to keep updating.
Con Very feeble raster tools
You have to go elsewhere if you want something more complex than basic vector masking of raster images.
Con Limited compatibility with Photoshop and Illustrator
Although it is possible to export certain Adobe file types in Sketch, compatibility is mostly hit and miss. For example, some elements seem a little offset in Adobe products.
Con Too many possibilities, no unified workflow
The operations are not optimized enough for specific tasks.
Con The physics engine is a bit lagging behind, especially the destruction physics
Con Difficult learning curve
Blender has a history of being unintuitive, but the 2.8 overhaul made the program far easier for beginners to pick up, and changes continue to be made to further improve the experience. However, there is still a learning curve.
Con Not good for Industrial Design because it uses average vertex normals
You can not create a hard surface with a radius continuity degree along a surface using a specific radius value.
Con Vertex normal issues on edges after boolean operations.
After creating a simple boolean operation the vertex normals are broken. A lot of work to fix the issue and you loos surface continuity.
Con Bad vertex normal after boolean operations
Does not handle well polygon intersections. And need tweaking by hand points or adding average vertex normals via modifiers.
Con Does not handle NURBs
Is not capable of real hard surface for industrial design because is not able to reproduce surface continuity degree as a NURBs does and average vertex normal destroy surface radius.
Con Poor particle system
The Blender particle system can at times be a little limiting and finicky (and buggy) to get working. Even if it can get most straight forward jobs done, it is far from the most advanced system, and could benefit largely from advancements.
