To me it's just not an encrypted messaging app. I don't even get all the discussions about it...

It's a bit like if we analysed the E2EE guarantees of email over and over again. Every year, multitudes of people would publish a post explaining how email is "badly encrypted". Well, email is not E2EE, period. If you want E2EE, use a system that has E2EE.

That would be fine unless Telegram

1) Didn't say it was "Heavily encrypted" on its front page.

2) Didn't claim it was more private than WhatsApp which is always end-to-end encrypted with Signal protocol.

3) Didn't claim secret chats were somehow adequate.