One of my biggest problems with Telegram is that they demand your phone number before you can use the service.

This is a problem with Signal as well.

My phone number and my identity is none of their business.

Telegram still, AFAIK, has no way to backup or transfer E2EE conversations, and no desktop support for them either. Those are non-starters to me.

Your encrypted conversations are stuck on the device on which you set them up with no option to change phones, continue a conversation on a desktop, or re-install the app. As a result, most people that communicate with me on Telegram use the standard non-E2EE conversations which makes it about as bad as (if not worse than) WhatsApp, privacy-wise.

While I like Telegram, I'm not sure if moving from an app with end-to-end encryption to one that either doesn't use it by default (for direct messages) or doesn't support it at all (for groups) is a good idea.

I get the idea of avoiding Facebook, but Telegram can see your messages in plain text...

Do they provide E2EE for desktop by now, or still available only for phone? I would rather stick to Element, Wire, or XMPP (gajim on Linux, Conversations on Android from F-Droid). Briar seems cool, too, but it is not available for desktop.

You misspelled "signal"