In Youtuber’s hand-folding test (live stream), the Razr Plus broke after 126,364 folds (hinge gave up after ~44k folds) while the Z Flip survived 273,316 folds (but lost ability to stay fully open after 223,000 folds) and is still going right now in the live stream.
EDIT: the Z Flip is now at 275,203 277,350 298,500 300k folds!
If you want your phone to last 5 years, at 223,000 folds (for full functionality including the hinge), that gives the ZFlip ~122 cycles per day, every day.
At 44,000 folds, the razr gives you ~24 cycles per day.
If you don’t care about the hinge then that same 5 years gives you:
Z Flip: ~150/day (and counting)
Razr: ~69/day