It still goes to active user counts though. There will still be a footprint left by any view and that can be marketed as "we have X million users daily!"
Again, the point is that those accounts are still users that can be pointed out as such for all to see. Remember: a youtube account is just a Google account.
One could argue that youtube is a highly effective loss leader - people get into the Google ecosystem because of making an account to subscribe to their favorite content creators. Now Google has data they can sell, and metrics for advertisers to go "I see 18-30 year old white guys who watch things about X are likely to respond positively to things about Y." The algorithm, even without advertisements, is constantly building a profile of every user.
The effort/cost expended to go after a tiny group of people vs the amount of money generated/saved from stopping them was (and probably still is) not worth it. There just aren't that many people who use 3rd party services without accounts.