Which phone on the market has the best hardware sexurity?

Calyx is a privacy group, they are legitimate. I would suggest using the RiseupVPN.

Do you not know how communication through servdrs that run proprietary software works?

Telegram is free to censor whoever they want.

If you don’t like it, host your own messaging service. If you use specifically Telegram expecting total freedom and privacy, you are gullible or ignorant.

Start a SimpleX group chat.