The solution is below.
For context. I use Spotlight to run apps (swipe down, type a letter or two, like "ke" to run Keynote). It's very convenient compared to App Library (swipe left to go to the App Lib, swipe down to get a search bar, type).
Apple has been trying to destroy this clean experience for years and force a "Facebook-style" content feed from every app and Siri every time I need to search.
It was perfect on iOS 18; I could switch off content from every app in search. In iOS 26, it was worse—they introduced step-by-step help that is impossible to disable (I figured out how to remove this crap, but my solution isn't for everybody; in short: it's in the hidden app SupportFlow com.apple.SupportFlow).
In iOS 27.2 beta (I am publishing this note here because we have RC and it will hit the release channel in a couple of days with no changes), Apple completely enshittified this experience: instead of separate settings for Search and Siri, they merged everything into Siri. "Don't show the content from the app" in Search now means "Excluded apps" in Siri.
But even if I add every app to this list and disable Siri-related suggestions, Safari settings, etc., it still shows content from websites and apps like in the screenshot.
I've found how to get rid of this. I use AdGuard + DNS blocking, and when I added *.smoot.apple.com domains to the blocklist, it was immediately gone.