The reason your ads are of terrible quality is because it doesn’t know who you are. You’re not logged in and it doesn’t have any cookies to go off. If I open an incognito window at work and watch a YouTube video it is HORRIBLE. Get rich quick schemes, cheap Chinese scam products, etc. There are a tonne of employees behind this IP and it’s a blank slate browser, so they give untargeted ads.
Think of it this way: Tech companies want to know everything about you, why? Because it helps them sell you for targeted advertising. If Dove wants to show their shampoo commercial to women age 14-30 then Google will gladly offer that for a price. Untargeted ads are literally bottom of the barrel ads and can be considered the “junk mail” of advertising. That’s what you get when you use YouTube without an account. It’s honestly despicable what Google will allow to be sent out in this category and it’s clear they don’t do any human reviews before approving the ads for distribution.