It's not just RAM it's also disk space usage. For instance Atom (text editor) takes more than 800MB of disk space on my Mac.
Back when I had four megabytes of ram I wouldn’t have been furious over a 50kb editor. 200mb isn’t a lot when most developers are working on systems with 16gb or more of memeory.
Yes, I hate Electron with a passion. It's a slow, wasteful framework for lazy developers who can't be bothered learning Qt or something else non-silly. IMHO.
If a dev is working on a less capable machine I guess I can see why this is a problem, but a rather simple one to solve, close Slack, it’s a distraction to focused work anyways :)