Slack ruins all my laptops from $3000+ latest Macbooks to my HP Pavillion - it eats up memory like Crazy. Using Slack for 2 years now and they still havent fixed it.
Sadly it’s the future, now electron apps are mainstream. Im not sure what they are doing with all their billions
Maybe not an option for you, but I don't leave it running on my desktop and instead rely on the mobile app for notifications and then pop into the desktop app if I need to engage extensively.