The only way to accomplish this at scale is to build something that is legit better and let the market decide. Anything else is just principled wishful thinking.
Microsoft Teams "won" entirely because it was given away free with Office. Even though it is acceptable these days, it was horrible when it started. There is no way it could have won without unlimited backing from a bigger force.
You have to see EU trying these things in the same light.
Yesterday I was supposed to have a call. I have the app open and it never once let me know that there was a meeting. The entire purpose is supposed to be collaboration with other people; if they aren't going to notify me on the web app, what's the point?
I know a lot of it is because of their need to support an infinite number of potential configurations, but if it had been a protocol instead of an app, we would have had the perfect frontend by now. (But then, how would they be stealing all of my data?)
Lol, we use WebEx, and someone actually went and developed an internal app to make it usable by piloting WebEx through accessibility APIs (including starting the call a minute before the meeting starts).
So it's not just a failing of Teams.