YouTube and the others all low-key hate ad revenue models. That's incredibly fickle revenue and it tends to suddenly crash, anytime the economy slows a bit, whilst the running costs stay up. Subscribers are more loyal.

And the ad revenue sources are often highly political and hit you with one boycott and shitstorm, after another. It's a never-ending nightmare. That's why stock prices for these companies only really get a big bump when they gain subscribers and contracts, not ad revenue.