That's less of a problem with Matrix. I set up a WhatsApp bridge because all my friends are on WhatsApp, and now I can use any matrix client, even a very lightweight CLI one, to talk with them.
> To be fair, for an internal communications usecase you just need to convince your company, not half the world
I imagine that's true for companies whose users stick to internal workspaces, but often the most active/vocal users (1) participate in multiple (often professional) non-company workspaces, and (2) don't want to run Yet Another Chat client.