Pro Built in sidebar apps
Messenger, WhatsApp, telegram and many others are built into opera, with full customisablility to remove any which are unneeded. These apps do not impact performance negatively and are a great way to stay in touch with people when you're on your pc rather than phone. Sidebar can be hidden with 1 click if you need distraction free time and renabled just as easily.
Pro Opera can have extensions from Opera Addons & Chrome Store websites
Opera supports cross-browser extensions. Opera Addons site keeps quality up compared to Chrome Store. Full of useful extensions, Opera also supports extra APIs like Speed Dial API, Extension Sidebar API and Stash API meaning wider variety of extension possibilities than in Chrome.