Yes I was originally going to use Ubiquiti cameras and PoE for this (Ubiquiti cameras store data locally too so a single chunky UPS would cover everything) but for me the problem was the cable runs. They were just not really feasible in my house without considerable work - there was no easy path to run cables under floorboards or through loft spaces etc - I would have had to cut channels in interior brick walls, install conduit, replaster, repaint, then pull the cables through etc. For one camera location I would have had to go through a bathroom too so would need to retile! It would have been the gold plated solution yes, but would have required
significant work and disruption to install.
With WiFi cameras I was just able to spur into nearby power which was already wired into the house. Each camera took maybe 30 minutes to do a neat clean permanent install. Running ethernet and making good would have taken many days potentially weeks, and as others have said it is mostly about deterrent and peace of mind.
It is easy (and kinda fun!) to get paranoid and get carried away planning all this stuff out and thinking about "what if..." scenarios, but ultimately home burglaries are typically just opportunistic things without much premeditation or planning. Sure if you are a specific high-risk target and people are going out of their way to target you then sure go ahead, but you'd probably just be better off with dogs at that point!