I don't doubt they make tonnes of revenue from ads however you have to remember how small the share of adblocker users are. So the extra money from fighting the adblock user base is a clear gamble. Especially as those types of users are the ones who are more likely to avoid YouTube completely if they can't bypass ads.

Someone in Google would have done the research because it's not a simple case of war profit = adblockusers * ad revenue per user

I strongly believe they'll stop once they hit a certain threshold/target of "reduction of adblock users". They won't go on like this forever.