> I think it improved quite a lot.

Maybe on Windows. My work machine (running Big Sur) currently shows:

Slack: 251.6MB

Slack Helper: 10.2MB

Slack Helper: 48.3MB (Yes, there are two of them)

Slack Helper (GPU): 316.2MB

Slack Helper (Renderer): 350.4MB

So just shy of a gig of RAM for chat.

It definitely has improved. It was clear from the memory usage vs community size that they were doing something that scaled with community size. This is a guess, but something like loading every single user and their profile icon into memory.