As for your ethernet example, that's too bad. Wifi capabilities will get better for every year that passes, too.
I beg to differ. I've gone from 802.11g to n to ac and I've yet to see any noticeable gains bringing me even close to plain old Gigabit ethernet.
It cannot compete nor compare when it comes down to even individual aspects: reliability, individual throughput, total throughput (due to shared medium access), nor setup speeds.
I'm not just talking "a little bit slower". I'm talking 1 minute guaranteed to succeed (ethernet), vs 1 hour guaranteed to fail (wifi). In real world performance, it's orders of magnitudes slower. That's measurable. That's a fact.
For lots of use-cases wifi is utterly useless. Have fun trying to backup media to a iSCSI volume over wifi for instance.
I'm guessing you don't live in a heavily populated area where the wifi-bands are over-consumed and have little more effective BW than 25mbps to offer. The same crap I was promised would improve half a decade ago. It haven't.
A huge part of the tech-hungry power-users lives in these places and suffers through this subpar performance. We're not happy with mediocre wifi to cover our needs.
"Who uses cable Ethernet these days" - I had to twice in the past year - a hotel in Germany that provided internet via a cable. And when the router decided to loose the WIFI password and I had to use an old laptop to physically connect.
I don't use USB sticks very often myself, but I am sure there are tons of scenarios where people find it useful. Just because it doesn't match any of your use cases is no justification.