[mr_custard]

Also adding: Slack Helper eventually goes into a death spiral and uses almost all of the CPU under macOS. I have to force quit it every other day or so. Slack seems to have been doing that for roughly 2 years.

Slightly mitigating data point: Other Electron apps do this too.

[markmark]

I have never had this happen on my mac running Slack.

[mr_custard]

Perhaps it's down to hardware differences then, assuming that you've got a newish machine. This is a fairly old MacBook Pro which will be replaced soon. Hard to say what the cause is, but I don't have any issues with other non-Electron apps.