That's not true at all, there are folding phones that are the same thickness as a regular phone when folded. And they don't compromise on battery life, like the Honor Magic v3. And Apple isn't a stranger to making things smaller than the competition on the mac side of things.
Unless Apple starts kneecapping their regular bar phones or comes in with a better price I don't expect them selling better than the Samsung Foldables in terms of bar phone vs foldable share.
Looking forward to seeing some diversity in the lineup. Apple are good at seeing what works and making it better but every phone since the X has been virtually the same with only small updates so good to see them try something different.
Give me a see through phone. Give me a light up chassis. Just do something.