I've had so many services over the past 25 years or so, at this point I
don't do any more than I have to. I like slack because it's business
partners and customers mostly so professional, and it's pretty universal.
I ran discord for a bit last year for a game I was playing, but that's
about it. I still use gvoice/hangouts for all my sms, signal atop that,
and that's about it.
As Hans said, Plug does have IRC, but of all things IRC is one thing I've
never gotten into using after all these years, or more never had a reason
to continue using. Perhaps less is more and should though.