I’ve used Ethernet over coax in my current apartment.

It’s worked well!

You do need to be a bit careful as coax signal can be shared with neighbors and others sometimes.

You can isolate your ethernet over coax from your neighbor with a MoCA POE "point of entry" filter which blocks the frequencies used by MoCA.

You can buy them online for around $10 and they install without tools,

Besides neighbors, you may also need a POE filter if you have certain types of cable modem.

cable companies require poe filters. if they find that there is some "noise" leaking from your house, they may put a big filter of their own outside, that can degrade speed of modem

I used those during covid to get a reliable connection for video calls and it was a huge step up over wifi. The bandwidth was like 1/10th of actual gige, so I got a wire pulled to my office when I went to fibre but there’s no question in my mind that decent powerline adaptors are the winner for connection stability.

For PoE you want two networks for the best performance. One for each phase of your mains.

In general they do suck, but they can be pretty decent if you stick them all on one phase, even better if all on the same breaker.

Powerline Ethernet != PoE (power over Ethernet)

Yes, no idea what I was thinking when I typed that. I've used both extensively, in fact this message was sent over a PoE enabled WiFi AP.

For maximum comedy, I'm imagining running powerline ethernet to supply a network drop to a PoE switch, which then powers the AP.

I have literally done this many years ago. Not a Cisco 2960 or anything fancy, just a dumb 802.3af PoE switch.