Telegram’s backend is proprietary software and they (very similarly to Discord for example) can just decide to read your chats whenever they want. It’s even worse then WhatsApp in this sense (at least as long as you trust Facebook that they actually encrypt your chats, again, there is no way to know if it’s proprietary software).

Just stop using the spyware ones?

You can move around and change your “home” server at will

How does that work? I know that it’s an option on Mastodon, but from what I understand, this is yet to be implemented into Lemmy.

Edit: spelling