Ok, but Telegram isn't Instagram. It's not even a social network, it's an IM. And while you can talk about lock-in effects with IM applications, I honestly think there's only one where it makes sense, and that's WhatsApp. In many parts of the world WhatsApp is completely synonymous with sending a message or making a call, so not having it cripples you. They enjoy market leadership on account of being the first player in a market that screamed for a solution way back when SMS and call pricing was horrible compared to data (and I guess in some places it still is). I strongly doubt Telegram enjoys any kind of similar effect, the percentage of users that can (and may) drop the app like a hat seems to me to be a lot higher.

Of course, I might be wrong, but the difference I'm trying to get across here is that unless every hair salon and restaurant you go to has Telegram stickers in the window (they don't), it's not comparable to Instagram, because switching to a new IM is for a lot of people like switching channels on a radio, the FOMO of losing all your friends is not as prevalent because people are already using multiple IMs and are much more open to trying new ones than they are trying new social networks, because IMs are "light". They don't want their IMs to be social networks, and the reason some of them are becoming social networks is pretty clear: it helps with user retention and lock-in. It's one of many reasons why Signal deserves praise, they don't bother with that.