I get that people don't like facebook but what's wrong with FB Messenger? For me I use it about 98% of the time. I does not require my phone number or access to my contact list, unlike many other messaging apps. It easily accessible on all of my laptops and desktops at messenger.com, no stupid "must login via QR code on only one device at a time BS". Also no app required on desktop (I trust the browser's security more than native apps on desktop)

It's also accessible across multiple phones if I decide to use a different phone. I have 2 with different sims and so sometimes, especially when traveling, use the other phone.

It supports groups just fine.

Also I've had almost no issue using it for audio or video calls.

I detest Line, and I detest WhatsApp. I only use them for a few friends who prefer them.