[floren]

IRCv3 ticks a lot of boxes server-side; you get chat history, user accounts (you can even log with the same nick from multiple clients), replies, and a bunch of other stuff.

Some clients show link/image previews. I think the #1 thing that would make them better would be configuration options to drag&drop/paste images and other files, and have those automatically uploaded to a user-configured service with a link dropped into the channel. Hassle to implement, though.

[welterde]

Polari [1] seems to support automatically uploading images and text to some imagebin/pastebin and then posting the link to the channel. The Lounge [2] also supports it (with the files self-hosted in thelounge instance).

[1] https://wiki.gnome.org/Apps/Polari [2] https://thelounge.chat/