I only noticed this when I started getting ads that had soles of feet included in pop up ads and video advertisements.

I love the feeling of squishing cow dung with barefeet. Recently, an advert has appeared of Gordon Ramsey stepping in cow dung.

Years ago, videos of naked black men would also appear in YouTube ads.

More recently, there was an ad where a woman had the soles of a dummies feet next to her face and was sniffing them.

I have no doubt, YouTube is using adult content that you watch and searched that you make, to create ads for their site, which means they would know your entire history of watching all adult content. Advertising agencies would also know all of your kinks and preferences and are using them to make money out of your own sexuality.