As a possible explanation for this issue, I think that if you use the internet to share data, it's more likely that Google makes money from some of the interactions (either via ads in the app or via play store tax or idk because the service is hosted in GCP or whatever) than if you used an internet-free method, so Google doesn't prioritize bugfixes that would hurt their revenue. Edit: would love to be proven wrong though!
Wikipedia tells the sordid story: https://en.wikipedia.org/wiki/Media_Transfer_Protocol#Compar...
Nevertheless, it's still removable storage that can take the place of the most common use case of portable flash drives: moving files around from one computer to another. Which is explicitly what we were originally talking about.
Pointing out that it doesn't work for some other use case that you yourself brought up doesn't make any sense. That's not what everyone else was talking about.
Ultimately this is an argument about the precise semantics of "removable storage". I don't regard an MTP device as "removable storage" - it's another computer that one speaks to using a special protocol, with severe limitations. So is an iPhone - with special, protocol-speaking software, you can certainly put arbitrary files on it. I interpreted the parent to mean that they wanted to plug the phone in to "any PC" and have it Just Work. MTP isn't so great at that, especially from my perspective as a Linux user, where MTP support is no more built-in than iOS-protocol support. From this standpoint, "removable storage" == "USB mass storage".
On the other hand, it sounds like whatever Apple provides is much worse even than MTP, and less well supported in general.
