Basically this. One of my favorite insights from an episode of Masters of Scale about Slack[0] is that products like Slack don't necessarily have to achieve huge network effects in the traditional sense to be successful, because you can convince companies to use it for specific teams, projects, or even company-wide, and then grow one company at a time. I'm currently using Riot/Matrix for things I'd usually set up a Slack/Gitter/Discord room for. For most of my friends they associate Riot with whatever the purpose of the chat room is, but at least it's a foot in the door from my perspective.

[0] https://www.stitcher.com/podcast/stitcher/masters-of-scale/e...