Do you have uBlock or some similar ad blocker installed?
EDIT: I went and looked myself. I do have an ad-blocker installed. I don’t see the ad. But I do see more noise than OP (desktop, Firefox):
There’s a set of steps at the top left telling me to download and install the software, which is what OP was complaining about.
At the top right, there’s a large, blue button with a link that guesses incorrectly that I want to know about Logitech Unifying Receiver Pairing, and just sends me to another Bing search.
Beneath that, there are a list of several questions that Microsoft incorrectly thinks I might be wanting to task and their answers.
Then there are two “Explore more” links linking me to pages describing how to pair with the software. One appears to link to “logi.com” with apparently is a Logitech business support page that links to the software, albeit only the Mac version, which I’d guess isn’t what OP wanted.
Back on the left, I have what appears to be an AI spam question-answer site at thewindowsclub.com and another page on “how to unify” at robots.net.
Beneath that, I have a link to the Logitech download section. So it’s in my top results and on my laptop, visible on the first screen of results, though beneath some not-really-desirable stuff.