I spend around 30%, if not more of my work time on Slack (collaborating with others, solving customer issues, searching, documenting)
I want that experience to be good, and not using a subpar tool like (Teams, IRC etc)
As a rule of thumb, I want to use the best tool available for the job, IntelliJ for the IDE, the best coding model (whatever that is at the time), the best Video call tool, the best monitor, the best keyboard etc
Although best is usually subjective, in some of this cases what is "best" is objectively clear, in some cases the gap between the best and the next one is small in others is huge. In the case of communication tools I think the difference is huge.
Is this needed to do my work? nope
It makes working more pleasant? definitely yes