Telegram is not the most popular messenger in Russia. It's not even in top-3 as far as I remember. But it is widely used by people who tend to be opposite to the current government (young professionals). Also, there are a lot of anonymous Telegram channels curated by the opposition.
Telegram was reported by one of three russian cellular network companies as 2nd after Viber by number of clients (both each day and simultanious peak) nearly a week prior to blocking.
Not only Telegram still working here, but it was a great experience yesterday.
Imagine the following: a manager in a supermarket explaining how to setup a proxy to a customer so that she (a woman in her 60s) could use their bot again.
Or a woman with a kid who is asking what the are going to do: "It's okay, we'll ask dad and he's going to do proxy-something".
Similar things long going on in Crimea for the same reasons established by the other side (whatsapp and viber are blocked by whatsapp and viber owners correspondingly). When I was there, everyone seemed to have a vpn on their phones and getting it installed was none of a problem.
Smarter people are better!