You just bought a washing machine... could I interest you in a washing machine?
While this annoys the hell out of me too, there is a semi-logical explanation that makes sense in many cases: The ad targeting knows you looked at washing machines, but doesn’t know you purchased.
However, they've been like this for over a decade so it's likely there intentionally. here's one way that could be possible:
There could be some popular third party service that's integrated on many e-commerce sites that sells this information and doesn't actually give a damn if you bought the refrigerator or not. They're selling you, not the refrigerator.
That's the problem with data brokers, it's mostly low quality data.