There was a surge of signups when WhatsApp changed its ToS to allow businesses to record/save conversations. Signal had issues with signing up. At that time it also didn’t support LG G4 phones anymore.

Signal didn’t work for some back in 2021/2020 and wasn’t supported on old devices, now I’m stuck with Telegram.

At least I’m not part of FB’s social graph and have some friends that now use something other than WhatsApp