And isn't that the same story in any business? They'll raise costs to the limit of customers' endurance, or else reduce quality to compensate?

If there is a problem then the problem is Google. I don't think this can be blamed on just the ad-driven profit model.

Not a business that is purportedly just a publisher. The channel creators were told they could choose their ad model. That was contradicted by this decision.

Imagine your letter carrier started stamping Aunt Agatha's letters with car ads or whatever.

The USPS is ad supported. They invented spam.

Aunt Agatha's letter is ended by junk mail.