I'm still using WhatsApp as it's so so okay with privacy still (messages should be end to end encrypted),it frankly works great and intuitive and the competition is frankly "meh". The web app of whatsapp is frankly awesome though lately it's been having weird issues with Firefox, thinking I'm running v60 or something and refusing to load for about an hour,, then a reload suddenly makes it work. It's weird, but beyond that, it's awesome and I can't live without.

Signal and telegram both lack a buttload of features, signal is barely functional and has many problems with basic usage

Believe you me, I'm an open source guy. I switched to Linux 25 years ago, and 20 years ago it was my only desktop. I almost exclusively use open source software where possible, and I'll jump off telegram as soon as there is an open source version out there that can a) compete with WhatsApp in functionality and intuitively, and b) I need to be able to convince my social circle to use it.