Google is now testing showing related searches based on your browsing. I suspect this is based on your browsing history on Chrome, beyond what you may search for in Google but based on what pages you browse.
This related search box is titled "Related searches based on your browsing."
It is not 100% clear, as Google may just be messing with titles on this box but it might not be using browser data.
This was spotted by Sachin Patel who posted the screenshot on X:
Google does do related searches based on your search history, other search history and what users click on but browsing history?
Forum discussion at X.
