Google might have just lumped you into the idiot bin, there are people who WANT their searches to look like spam. Google will happily show people what it thinks they want based on how they've interacted with the service (or sometimes, how the people on that IP address/machine have interacted with the service).

I always have to start an incognito tab to find anything that isn't pure drivel on my mothers machine. Otherwise I get search results that look remarkably like the spam she forwards me.

Try a search from an incognito tab and compare.

She might have malware. My parents' machine had a malicious extension that made all the search results terrible.

It really depends what you're searching for - product reviews are an endless landscape of garbage, science-related stuff is pretty good.