For the longest time, Steam's built-in chat functionality has not been what I would call good. Today, though, Valve revealed a much-needed modern makeover, and you can try it now.
Steam's new chat functionality makes friends lists more flexible, allowing you to see what friends are up to and organise people in a variety of ways, including - most intriguingly - by group. No bones about it: Steam's new persistent group chats are basically Discord.
You can make individual channels, use voice chat in them, and even access your group chats through a web browser instead of Steam. They allow for embedded media and all that fancy (as of several years ago) jazz, too.
The new chat features are now in open beta. Valve says it will release the functionality in full when it's "confident that things are working as they should, and we've finished up some of the features we have planned".