All hope is not lost. I recently returned to using my Wyze cam v 3 after a hiatus of a few years. Now they are still brand new as I never got to using them when I first got them. Fast forward to today when I tried to turn them on, only 1 did. The other one simply does not turn on, whether I pressed and and held the setup button for however long, or whether I tried to delete it from the app and factory reset.
Then I came across a poster saying he opened the wire on the back of the unit and discovered it was disconnected. He thinks it was caused by the constant turnings of the rotatable base. While mine was not disconnected after I opened the tiny rubber cover where the wire is, I did try to blow away some visible dust and just replaced the cover. I then pressed the setup button again and it worked. The light turned on.
So long story short, don’t give up hope on your camera. If all else fails, why not try this method. Good luck!