i.e.: https://www.welt.de/vergleich/stabstaubsauger/ https://www.krone.at/vergleich/staubsauger-test/ https://www.stern.de/vergleich/staubsauger/
These pages are in all regards very well created, they strike all SEO best practices, have zero affiliate links (as they are hidden behind javascript) and fulfil all SEO content quality guidelines. And are constantly updated.
And they are in all regards, SPAM. Always the same rotation of products get recommended, and win these "tests".
They are so widespread and this is going on for years, as Google clearly must know about this. But they choose to do nothing about them. Probably as they are looking for an algorithmic solution. Well, it does not work.
And Product search for popular every day technical products has become unusable for years now.
Google must have become a deeply dysfunctional company to let this go on for so long.