Yes this is a Telegram client and yes it will break the Lemmy’s downvote world record but I still find this one very nice and “actively” maintained. There are not many good Telegram FOSS forks without Google integrations and similar stuff out there.
The options are basically:
Matrix if you want a Discord-like experience
XMPP if you want a whatsapp/google talk like experience (both of those are based on XMPP)
Signal if you want hyper-secure chat and don’t mind some mild inconveniences in things like registration or desktop apps.
All three support or can support E2EE.