YouTube doesn't have to adjudicate anything. They just have to demote the known bad actors to using the real DMCA process rather than their own system. They can still make a claim under penalty of perjury with a takedown but that won't count as a strike.
There's actually a lot of history (going back at least as far as 2007) that led to the current situation where the DMCA is not the process. In fairness to YouTube, they had significant legal pressure back in the day, including suits and credible threats thereof to go beyond the DMCA... which is exactly what they did.
We can speculate to if the current situation is the natural conclusion of those agreements with major IP holders, or if they simply got religion and now embrace those practices... but at least historically, it wasn't simply management discretion which started them on this path.
I don't dispute there are things they can, and should do, nor do I dispute that their current management of the problem sucks.... but it's not quite as simple as just taking a decision to abide by the DMCA as-is.
Yes, YouTube was sold to Google essentially at gunpoint. But since then the balance of power shifted from Hollywood to Google. So they they would benefit from relaxing this policy.
