Yes, it is - because it's actually 2500 videos per MINUTE, not per hour, mea culpa. So your 30,000 reviewers would actually have to be at least 1.8 MILLION.
It's not about the viewing time, though, it's about the videos.
The misconception is that it's the review process that's the problem - it isn't. That can be automated just fine.
The problem arises as soon as there are complaints or issues with the content and that depends on the number of videos, not the duration.
So if there's a problem with a video it can get flagged, de-monetised or even taken down automatically by software (as is the case now). This is a non-issue. It gets complicated as soon as one party has a dispute over this and that scales with the number of videos, not their length.
> that scales with the number of videos, not their length.
That seems pausible, but if so, the entire calculation would have to be redone from scratch, with qualitatively (not quantitatively; different units, not just different values) different numbers, so bringing "1.6 million" into it is still a misleading non sequitor.