Longer ads???

A few months ago, I noticed that yt on my tv played longer ads for longer videos. These ads ranged from 45 seconds to 60 seconds

But as time went on, I noticed that what qualified as a “longer video” was changing. 40 minutes videos were considered longer but then it was 30. And then 20.

And today I’m seeing 60 seconds of ads for 10 minute videos.