https://www.pcgamer.com/valve-releases-a-new-and-very-improved-chat-client-for-steam/

Valve has released a brand new chat system for Steam, with a bevy of new features including a customizable (and prettier) friends list, group chat options, more seamless voice chatting, an invisible mode, shareable friend request links, and more.

The new friends list enables favorite friends, groups, and chats to be maintained at the top of the list, where they're easily accessible, and they can also be grouped by game or by party, making it easier to keep track of who's playing what, and who's playing together. Game developers will now have the option of including other information in list entries as well, such as where players are located in their game, or whether they're available for matchmaking.