Well Chrome(ium) has almost all of the browser market share and google is trying to push something called web environment integrity which would implement a sort of certification system where web servers evaluate the authenticity of the client. If you extrapolate that idea a bit further it boils down to "we won't serve you content if we don't like your browser, device, OS, etc". Which I would consider as hostile to the open but rapidly closing internet as we know it.

Edit: I forgot to make my point lol. Firefox is a completely different browser engine from the chromium based browsers which is why you see a lot of people recommending firefox because they don't comply with web integrity. I don't think it's working though because this is something only the techbros and the cybersisters care about while everyone else just goes about their day.