Why is targeted internet advertising so horrifically inaccurate?

I tried an experiment this week. On Chrome, I used my normal array of ad blockers, un-trackers, and similar protective measures.
On Firefox, I used no ad blocking or anything else – everything was allowed.

And I tried to use Chrome and Firefox pretty much 50–50.

What I found is that the internet-based targeted advertising truly sucks. If I were an advertiser, I would royally angry that my good money is being so badly spent.

Among the badly delivered advertisements:

- ads to become an Avon sales drone (I’m male and don’t use cosmetics)

- at least a dozen ads in Spanish (I’m an english speaker and don’t know more than a dozen words in Spanish)

- Ads for diapers (I have grandchildren, not children, and some of the diaper ads were in Spanish)

- two ads for banks in New Mexico (I live in Georgia)

Why are these so-called targeted ads so inaccurate?