When comparing IRC vs Riot, the Slant community recommends Riot for most people. In the question“What is the best team chat software?” Riot is ranked 3rd while IRC is ranked 9th.
Ranked in these QuestionsQuestion Ranking
Pro Open protocol
The IRC protocol is public and open, it is mature and stable, and has been implemented in numerous projects. This means that it can be used freely, for both open-source and commercial projects.
Pro Hundreds of avaliable clients
IRC has been around since 1988, so there is a ton of existing software to work with it. Everything from clients, to chat bots, to bouncers is already built.
IRC offers choice. Choice in clients (mobile, desktop, web), in scripts those clients run, in servers and features those servers have. You can even set up your own server.
Pro IRC networks are not centralized
You can choose your favorite server for an IRC network.
Every notable IRC client supports mentions - notifying you when your name is mentioned in the chat.
Pro Great historic importance
Twitter hashtags came from IRC channel names.
Pro No account necessary
No need to sign up for access, confirm your e-mail address. Just choose a nickname and you're done.
Pro Less distracting
Compared to other common solutions, IRC can be ignored when you are occupied doing something else. Most clients don't pester you with sounds or distracting visuals.
Pro Upcoming IRCv3 will provide missing features
Pro Web and mobile (iOS, Android) versions available
Pro Supports text, voice, video
Integrates with Jitsi for multi-party video chats
Pro Uses Matrix, the open communications protocol
Pro Very good and simple interface
Riot has a very simple interface, adding the ability for more unexperienced PC-Users to use it.
Pro Widgets support
Want to watch that flick at YouTube and discuss it at the same time? Have Grafana graphs stacked above your DevOps team chat? Collaboratively edit Google Docs and chat over without switching applications? This is possible with Riot.
Pro Bridges to other networks
You're not confined within Riot's or even Matrix garden, and you don't have to make users of other networks switch to Matrix.
Con Poor multimedia support
Sending anything besides text is not easy or intuitive and depends on the client.
Con Complex and not user friendly
Con Advanced functionality is client-dependant
Con Assumes some level of prior knowledge
The features are not discoverable the way they are in other apps and services.
Con You have to "idle" to see what's going on
You will see a blank chat screen at first because there is no recent history kept on servers.
Con Can be addictive
Con Still in active yet early development
There is clearly a User Experience issue esp. in web version which the developers are aware of and are working hard to improve. They've got the concept concrete, so UX won't be an issue in no time. Most often used parts are functional, but some are yet not.
The success of riot depends on how fast the development is, or it'll get outdated too quickly as developers of Signal and Telegram have predicted.