No. Everyone is on Teams.
Slack won't be 'extinguished' but it will have a falling market share, despite the dumpster fire that is Teams, and the bean-counters in most corporations getting kudos from their bosses for 'cost savings'.
Ive been using them since 2021 iirc and they improved a lot
And im using Discord daily which is state of the art
Calendar and meetings are decent, chat is viable and I dont need more
Whats causing problems for you?
It's the least reliable chat program I've ever used.