The scale of data storage, transcoding compute, and bandwidth to run YouTube is staggering. I'm open to the idea that adblocking doesn't have much effect on a server just providing HTML and a few images, but YouTube's operating costs are (presumably, I haven't looked into it) staggering and absolutely incompatible with adblocking.
YouTube broke even sometime around 2010 and has been profitable ever since. The ad revenue has always been more than enough to sustain operating costs. It's just more growthism = more ads. If you want the YouTube of 2010--you know, the product we all liked and got used to--you can't have it. Welcome to enshittification.
Personally I find YouTube unusable without an adblocker. On my devices that don't have an ad blocker, it's infuriating.
*Bias disclaimer: I work for Alphabet. Not for YouTube. There's no employee discount, I pay full price for YTP.