I did come across non-English article that all-eSIM policy is destroying grey market imports into primarily China and also into Russia. Previously one could easily flip iPhone at or above MSRP to milk carrier subsidies, but those flippers aren't taking iPhone 16/17 as it's harder for the clientele in totalitarian and/or sanctioned countries to use it.

I'm not sure if it's an undisclosed security hole or a backdoor, but there does seem like the eSIM push has something to do with China.