What's wrong with Telegram is the privacy story. It's not end-to-end encrypted, meaning that the server can read the content of your messages.
I hear that Telegram has a great UX, which makes it popular. But in terms of security... it's wanting.
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.
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.
They have f'd up in the past, and since they still employ the same incompetent nepo-hirings, they will continue to f up in the future.
Until they own their mistakes and E2EE everything, like they should have done in the first place, I will keep pointing out their incompetence, past and present.
You do not get to rewrite their history by telling people to shut up.