It is ironic that many Android fans complain that iPhone users are ignorant about what features Android phones have ("haha, we've had that feature for years!") yet seem to have just as little of a clue what modern iPhones can do.
I recently got a 13 pro for work, and had to admit I was surprised at how good their software has become.
It was incredibly easy to have friends and family download the app and replace their SMS app with it.
Almost zero change or learning curve on their end, and we all got increased security when we used it.
Telling your parents to download yet another new app to talk to just you is a no-go and sabotaged their goal of increasing security for people at large.
OP seems confused about the different between a flip phone and foldable phone.
They are two massively different things.