Earlier quoted context omitted.
Slack took great pains to make the client not be a memory and CPU hog. Still better than Teams though. (Which is also in Electron.)
You can also see the pains the Evernote team took from the initial Electron-based 10 release until it became usable again. But you could also feel the product moving again after stagnation on a gazillion native clients. It was the right albeit mostly final engineering decision they took.
Also, still the app is almost worthless on my Android phone. Too slow, despite large improvement.