Because it’s impossible to block adblocking. The server can’t know whether the client plays the video. The best they could do is have you wait the ad-time even if the ad is blocked but that would just mess with their analytics - they want to be sure the ad is being watched.

The only reason adblock blocking works for smaller websites is because adblockers need to catch up with each implementation. People will easily catch up with Youtube as there are thousands of people working on Youtube programming.

Reddit had so much community favor too. The whole awards thing was born from people wanting support the website. If they really struggle to make money could have rolled out an optional subscription or something with a message that everyone would have fallen for. The incompetence is incredible.