Is there any way you can upgrade an iPhone in any way possible?

You’ve already asked a similar question the other day (Can you put an A11 chip into an iPhone 6 logic board). There is no way to “upgrade” an iPhone, with one exception which I’ll address later.

Every iPhone is uniquely designed and developed, with no consideration given to making it upgradeable. Besides, the technology in a modern smartphone advances very quickly so the technological advances in each new iteration is considerable. It may not seem that way to the end-user because we’ve grown accustomed to the basic functionality of a smartphone but the major elements are always advancing. A smartphone is not like a desktop computer which is designed around a standardized backplane with expansion slots. Everything on the iPhone logic board is uniquely designed to work with every other major subsystem. You can’t change one without affecting everything else.

Now for the exception. You can upgrade the amount of memory, say from 64GB to 128GB but that requires an invasive micro-soldering “repair” and it is expensive. So in reality, you are better off just getting the phone that offers the speed/memory/technology you desire and sell the one you have to help subsidize the cost.