ok, so my technical knowledge is limited, so correct if I’m wrong. I know that the content of emails is end to end encrypted (regardless of what runs on their backends), but emails have a header that can not be encrypted. so from what I understand, in practice it doesn’t matter that their backend is proprietary? because the header is exposed anyway and they can’t do anything about it? basically it’s the same problem with matrix, metadata can’t stay private, right?

still sucks that they’re not FOSS.

For example, one can be a Libre software advocate and wanting to use Tox and Jami and Briar only but if your colleagues, other parties/partners (you work with), family, friends etc. are not able or not willing to use that software then it is not going to work out.

I know, I still have to keep using whatsapp because of my college T_T