Honestly, I do find that Slack helps me focus.

I can pretty easily make sure that I ignore non-critical rooms, and only get notifications if someone @‘s me.

It would be really nice if as a user you could suppress all @here, @channel etc shouts and only enable them for a few specific rooms.

Overall Slack + 100% remote work has massively improved my focus and ability to get things done while remaining social and involved.