> That said, it would be nice if there was an easy way to turn off this search personalization on a search-by-search basis
it is, it's called anonymous window
it is, it's called anonymous window
When I open an incognito tab and search for “latex”, the entire first page of results is still all about LaTeX for me and I would bet my left hand that this is not universally true.
In other words, you are still seeing personalized results.