> our economic system requires prices to increase while product quality degrades to ensure ever-increasing profits for shareholders

Only in the absence of competition. Prices go down all the time while growth remains positive.

> why can't we just have something that's truly paid and ad-free

You can, it just costs more. Ads are a way to make sure that there's a product for more price sensitive customers while keeping revenue high.

The real problem for streamers isn't pricing, it's churn.