Telegram is way snappier and is more peformant all around. Same reason why people complain about Electron all the time.
> Where? On Whatsapp? Because on Signal you don't need the device. It can be powered off.
No, compared to Telegram. Messages you send via Signal on mobile are not available on desktop, and when you sign-in on desktop you need to first link with mobile. When they become out of sync the messages you had previously are no longer available.
> What are you talking about? I have the same messages on my phone and on my desktop client. I don't need to do anything. Just launch either.
Again, as long as your device is linked but if you lose/break your phone then the E2E messages are not longer available on desktop after a period of time.
> What is exactly "great" about it compared to the others? You can send the same stuff as you do with Signal.
Telegram has a lot of great features that are not available on Signal. I suggest you try it out if you haven't already, and if you have then maybe you don't care about those features but it is much more widely used than Signal for that reason.
> , and if you want end-to-end, it has that too but is mostly limited to mobile devices.
That doesn't make it worse per say. The process of linking on desktop for Signal is cumbersome. I don't think Telegram is perfect, which is why I think GPG would be a great solution for encrypted cloud messaging.