Kind of? iOS does have a file manager which explicitly shows you your own files. They just made a separation between OS/Program files vs the users own files. What more killed files was cloud programs where multiple users can edit at the same time which required a system that was more sophisticated than syncing a file.

Yeah, I'm not sure most normal people use file systems that much.

We spend ours on our laptops and assume others do too. But many people don't even own a laptop. They handle all their computing needs from their phones, using proprietary apps, with the data living in WhatsApp messages.