Making a wallet is a very big deal.. and using telegram to communicate with your API just makes things a whole lot more complicated cuz you're exposing your API..
Using telegram makes things easier:
- it already has 200 mln users
- I'm not exposing anything, API is authenticated
- I don't need to design website, think about it's security, etc
- There are let's say 10 commands with different arguments, unknown command will just not do anything, known command can be extensively tested with all possible arguments