Could be, I don't have any price info on all of the PoE lighting stuff.
But let's say i've got an office area, where I would need 2kW lights in total (which isn't much, I think 200W per desk is considered bright enough). This would need 20 PoE ports, 20 cables, 20 PoE-capable light fixtures with the right transformers/bulbs. Just the 2kW/>20port PoE-Switch will set you back 2k€ or more, no idea what the light fixtures will cost. Maybe a 50W ZigBee bulb will cost 50€, you need 20, then you are at the price of just the switch. And you can just use plain electrical wiring, no need to do the whole more expensive Cat6+Patchpanel thing.
And my personal favourite, even better than overly expensive ZigBee bulbs: https://www.shelly.com/de/products/shelly-dimmer2
Wifi-controllable dimmer, speaks MQTT or HTTP, for a load of 200W at 35€, works with any dimmable light fixture. Also available as a relay if you aren't interested in dimming, then you can do 2kW in 2 channels at a lower price. And if you are worried about WiFi, there is a cabled version as well.
I'm sitting staring at an 8W filament led Edison bulb, 800 lumens. For a zigbee bulb I found, 11W, 1100 lumens. And I think they include ZigBee overhead in their 11W? Don't even need PoE+ for that.
It would just come down to chip and maybe power cost difference between Ethernet with PoE vs wireless with traditional 120V electrical wiring. Pretty pointless to retrofit I'd think, but for new construction it could be viable.
Saw a 24 port Juniper PoE+ switch for around $450. EX3300-24P. And a 48 port variant. Only 400 and 700 Watt output respectively. But that is enough for ~15W per fixture, which should get well above 1000 lumens.
I'll admit that at a certain point it is a lot of switches to manage.
But let's say i've got an office area, where I would need 2kW lights in total (which isn't much, I think 200W per desk is considered bright enough). This would need 20 PoE ports, 20 cables, 20 PoE-capable light fixtures with the right transformers/bulbs. Just the 2kW/>20port PoE-Switch will set you back 2k€ or more, no idea what the light fixtures will cost. Maybe a 50W ZigBee bulb will cost 50€, you need 20, then you are at the price of just the switch. And you can just use plain electrical wiring, no need to do the whole more expensive Cat6+Patchpanel thing.
And my personal favourite, even better than overly expensive ZigBee bulbs: https://www.shelly.com/de/products/shelly-dimmer2 Wifi-controllable dimmer, speaks MQTT or HTTP, for a load of 200W at 35€, works with any dimmable light fixture. Also available as a relay if you aren't interested in dimming, then you can do 2kW in 2 channels at a lower price. And if you are worried about WiFi, there is a cabled version as well.