Google's great achievement, supposedly, is using its search capabilities to match ads to keywords in order to target people who actually might be interested in them. But anecdotally I would say that this leads to a high percentage of unintentionally hilarious, supremely inappropriate ads, whereas in days of yore perhaps this was more rare.
Whenever I clean out my gmail spam folder, Google Ads never fails to offer me some spam casserole recipes, and if I notice them I tend to have a double reaction of dissonance: first, the switch from thinking of spam in the sense that I've explicitly gone into this folder to tackle to spam-in-a-tin, and then the slightly ill feeling one gets from thinking of spam-in-a-tin.
It occurs to me to wonder why one would put ads on the spam folder in the first place. It is, after all, by design and definition, the place where unwanted ads go to die. But then, maybe that's the only natural home for spam casserole recipes.