For a very long time (ive not checked recently) slack used more memory that my IDE on a multimillion line c++ project. I used to have to shut down slack to compile on a machine with 128GB ram.
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.