In my circles, it became popular during the pandemic and a number 1 source of misinformation, with an unnerving amount of obvious links to Russian propaganda- covid related, yes.
So after seeing the extreme antivaxxers join the telegram train, and seeing how gullible acquaintances got "tips" from their telegram groups, I just couldn't take the app seriously. I understand logically maybe the app itself is better than WhatsApp, I understand this may be just my personal experience and that there was just as much trash on WhatsApp. But having my sane contacts using WhatsApp already and my family on Signal, I never saw the need to switch.