I don't know why you're being downvoted; it's a pretty interesting idea. A buddy mentioned a few years back that his church had moved their lighting over to PoE and ever since then I think that makes a lot of sense - I find it bonkers to think now that a room might have needed a couple hundred watts of lighting even a decade or two ago. Fluorescents and then LEDs really changed that game at least. A power-caching toaster seems feasible if a bit overly complicated, and vacuums may or may not work (I think the latest PoE spec is like 95 watts?)

What I don't like the idea of is needing to bring in a network engineer to troubleshoot my lights though (and I say that as someone who occasionally works on a variety of network gear as part of my job). I suppose unmanaged PoE switches need not be too complicated though.