They also do it on their Mastodon account.

I fully agree with you. Especially since Proton will never implement all the features that Thunderbird offers.

You don’t x)

More seriously, in these cases, I often rely on emails instead. But I don’t really use group chats a lot (even with my contacts that are on Signal), nor send many files, so it’s not features I really miss. And SMS works with everyone, so it’s always my default if the contact isn’t on Signal.

Indeed. I always connect as a guest through the browser. Never had any issues.