Reliability of wifi is not as good I guess, although these days it is extremely good for decent devices. For poor quality devices, I have also heard of PoE routers blowing ports and devices that don't work properly.

Is security of wifi an actual practical concern? I've not heard of it since WPA2.

For average residential user, even most hobbyist / enthusiast, I doubt those things will matter. Almost everybody who wants extremely fast reliable wired connectivity will be much better off using fiber, and using wifi for cameras and automation and streaming and other such things. Getting power to where you need it is not the difficult part, especially if you're pulling wires anyway, which is why PoE has always been fairly niche.