Singling out Telegram, or Signal, or any other service's devs is not advancing any argument forward.
Partly because it’s insecure by default, which makes a large percentage of conversations vulnerable.
And also because the team behind it is very susceptible to pressure from the Russian government, which is especially bad when it comes to these things. Even if some of them are based out of Dubai now, it doesn’t mean that they aren’t still at risk of coercion, either directly or through for example threats against family members who remain in the country.
If you don’t trust Russia, which you shouldn’t, then don’t trust Telegram with anything sensitive.
I for one trust that there are more Americans who would say no to the NSA when they have a legal basis for doing so than there are Russians saying no to the FSB.
The state of the rule of law is certainly not great anywhere in the world right now. But it's far worse in some places than in others. The difference still matters to some degree.
No, we cannot, so yours and other comments come across as picking favorites. As an Eastern European I'll state that I distrust USA as much as I distrust Russia, China and North Korea. All nations with ambitions use every dirty trick known to man.
Not to mention there's not much reason to trust UAE any more than there is to trust Russia.
As for E2E encryption, eh, this topic has been beaten to death many times. Its UX is difficult so many apps like WhatsApp and Telegram do UX tradeoffs, quite successfully so I'd say.