And that right there is how the "security" concept was instilled. I didn't really do much research because I didn't really care, which is on me. But that's how it was pitched, so that's what stuck.
Yeah, same here I guess since I can't really remember. I probably just noticed how popular it was and also just thought that it should be secure since that's also how it's marketed. Another aspect is that so many group chats are on TG. It also has a nice API for writing your own bots.
So I think it comes down to this: It's just very convenient to trust other people and outsource your research. And sometimes, it's also necessary in some way since we don't have time to do research on everything before using it (?).
Also, I have to admit, what bothers me is not necessarily that they don't use E2EE. What bothers me is that I don't really understand why they are not using it.
But I'll have to do more research on that, lol