Its better because: It can sustain big public groups (upto 200k peoples), channels with unlimited subscribers, unlimited cloud storage (files upto 4gb, synced across devices), powerful bots, web apps, native crypto support, you can do pretty much anything within the app (literally a superapp), heaven for pirates, stickers, video calls, live streams, etc. unlimited devices could be signed up for one account, messages sync across devices, free with minimal ads, premium to get more features, completely run by users support and ad platform, no external entity involved. secret chats for end 2 end encryption chats and much more.

Telegram is more geared towards group communication. It has a much better group chat experience and a channel feature that lets you disseminate information in a single place without a discussion taking place. It is better at group communications in that it is more feature-rich.

If you’re doing is 1:1 messaging or have some small group chats with 2-3 friends you wouldn’t get much out of it over Signal.