It's like every generation loses the ability to do something in computer technology that was just abstracted away somehow. I as a millennial have never soldered a PC mainboard (modding an Xbox doesn't count), but I'd say that otherwise, my understanding is pretty good. And I think all of my friends understand the concepts of files.
I recently asked someone about 10 years older if he knew what partitioning and formatting means in the context, and he knew, despite initially saying he has no clue about computers, to show someone 10 years younger (who didn't know) that such knowledge was just basically required back in the day. And it's not like these terms are obsolete, the concepts are still the same, even though we went from MBR to GPT and from FAT32 or whatever to better filesystems. It's no different for phones, but not required and even hidden.
I'd say generally, the technology userbase broadened while average knowledge in the group declined, however I'm not sure whether the absolute numbers of people with a certain knowledge level actually went down.
And people say this election was all bad /s