My grandma uses WhatsApp. The only reason I’ve ever used SMS is to receive a verification code

That’s a good tip. Also: have your servers auto-update weekly. You will forget.

Apple is willfully hampering the ability to intercommunicate between iPhones and Androids

In what way exactly? All the messaging apps I use work fine. I even have the same Signal account logged in through both my Android phone and my iPad.

Nobody I know actually uses iMessage either. It’s a complete non-issue as SMS is quite an outdated technology.

Yep just delete the account while you’re at it. If it’s for work just don’t use it on a personal device

I have an nginx reverse proxy with http auth, myself. It’s such battle tested software that I trust it fully

I like the concept but they’re too expensive for me. About €2k for a fold and €1k for a flip is outside my (self-imposed) budget. I don’t particularly wish to spend more than about €600.

Once they become more mainstream and affordable, I’ll most definitely be checking one out.