What's the actual use-case for this? I actually don't know anyone who uses Telegram, let alone apps on Telegram. But I'm also not friends with any crypto people.
It's pretty popular in Eastern Europe and Russia. In Ukraine railroad tickets are sold through a Telegram chat bot.
I think the main reason people prefer making chat bots in Telegram is that it's completely free and unlimited, i.e. you can create any number of chat bots, send any number of messages with attached files of any size. Their API is very easy to use too.