Strange. The other day I had a call on Teams with a customer and had no problems using Firefox 117.0 on NixOS, but I recall that some months ago some features (like microphone and screensharing) where unavailable.
Maybe Microsoft hasn’t rolled out the update in your region/org?
Well, Proton is a Swiss company and, as such, is obligated to comply with legally binding orders like the one they received in the case of the arrested activist. Expecting someone (or, in this case, a company) to risk legal repercussions just to protect one of their thousands of users is simply ridiculous, even more knowing that similar data access orders are normally issued by the Swiss authorities for really serious crimes. As for the IP logging, everyone can turn it off in the account settings and Proton, not being subject to data retention requirements under the Swiss law, will delete all the previously saved data.
More info can be found in this article they published just after the incident: https://proton.me/blog/climate-activist-arrest
Related XKCD: https://xkcd.com/806/