Claiming that (youtube) ads are bad is a tautology at this point. What else can be expected from something competing for what is left of a user's attention at the very lowest end of a market already overflooded with crud?

The question should rather be: why would one voluntarily let one's well-being be polluted by such invasive, parasitic crap.

There is nothing normal about ads everywhere. There is nothing healthy about ads everywhere. Ads are not an inevitability.

Run an ad-blocker, protect your mental sanity.