I'm sure there are ads you've seen on YouTube, they just look slightly different to what you have in mind.

But first, this comment wouldn't be possible without Deutsche Bahn, the n°1 train provider in Germany. If you go to their website right now with promo code "probably_wrong" you get extra delay on your next trip. If you're going to be late, be late with Deutsche Bahn. Remember: promo code, free delay.

Now, back to our comment. YouTube is full of ads, the only difference being who gets the money from them. Is one of the reasons why some people here don't want to pay for it - you get less ads, but not ad-free.