I'm no fan of Facebook either, but if they collapse and die one day soon, one thing I'll really miss is FB Messenger. I just haven't found anything remotely like it that works as well for keeping a friends list, letting me chat with them, and letting me do video chats, both on my phone and (very importantly) on a PC.

Everything else fails in some way, usually the PC part. Most chat apps have some video chat function, but it sucks and is totally useless because it's only on the phone; there's no way to do it on a PC, so what's the point? I don't want to see shaky video from someone holding their phone in their hand. I can chat with people using Zoom, but that's a pain because it requires a native application, it's only for video chats (not for keeping a long-running text chat), so while it's great for business meetings it sucks for personal use.