Comment by tazjin
People go through all this trouble to host convoluted chat systems, and all this time IRC is right there. There's modern servers like Ergo and modern clients like Halloy (or for the JavaScript addicts: Convos, The Lounge, Kiwi, ...) providing all the multi-device history sharing and emoji reactions you could need. All on top of a super simple, extremely battle tested protocol.
But according to https://ircv3.net/software/clients, none of the clients you mentioned actually support emoji reactions (draft/react), and other features like multi-line messages and image uploads are likewise extremely limited in server/client support. So, for the time being, you can't use these features if you want to actually be interoperable with existing IRC users and their clients. Sounds like if you want decentralized, Matrix is still the better bet.