Don't forget FS patches. XCI conversions (games that leaked pre-retail from a cartridge source) are a real thing that people like.
I really, really doubt it. Copying from a PC to a USB device and attaching that USB device to the Switch to install takes more time than installing directly from a computer. It's just common sense. Has nothing to do with what CFW has what.
I agree that there is a lot of demand for XCI conversions, thats why I added XCI installation support to Tinfoil even though I think its a dumb meme.
The issue with USB is that it requires running software on the PC and the installation of hacked drivers, which is too technical for most normies.