For comparison, Samsung Galaxy Z Fold is ~$1700.

It's good to see Apple is taking the fold transition seriously. I have a Z Fold, and Samsung elegantly handles the app transition from fold to unfold by force closing and restarting the app for you, even if you fold it just a little. :D

That only happens with a few bad apps that don't handle configuration changes properly for me on my Fold?

This was not my experience at all on the fold. Only a very few small selection of apps did this. All were video game related, which made sense. Changing the resolution forced a restart.