One thing with Reolink, for anyone seeing this, just be sure to get one of the hardwired (for power) cameras. I have a wired Reolink doorbell (which is quite nice) and a solar+battery powered Argus which is practically useless other than as a deterrent. The battery powered devices don’t integrate well, no video streams, and have very weak object detection.
ESP boards are so cheap that in my opinion this doesn’t make a whole lot of sense - it’s probably going to be more expensive than distributing ESPs around due to the wiring, and I guess I’d argue the distributed nature of HA/ESPHome is one of the best things about it, versus centralized alarm panels, for example, that used to be common decades ago, bringing all wiring back to a single location. Optimizing for unused GPIO pins isn’t really something that bothers me, personally. What I like about my ESP projects is just the opposite - that I can sprinkle them around the house close to the things they measure and control.
I don’t mean to be super negative - of course you should do it however you want to, but that’s my opinion - for what it’s worth (i.e. nothing).