Earlier quoted context omitted.
Showing your own product like google maps or shopping at the top of each relevant search result is likely over the line, maybe its ok if its down in the results, still high not always number 1. But for example if they're behind a user choice like a click after your search is done, ie click shopping or maps because you want to use googles products in this case, then its likely not over the line. If its still over the…
I don't really think of showing rich shopping results as preferring "Google's product". It's just showing links to merchants in a fancier UI. It's fundamentally still search, linking out to 3rd party websites. FWIW, even what you think should be allowed is banned in Europe. On Google Search in the EU there is no "Shopping" or "Maps" tab.
https://www.google.com/shopping is still available, just no link to it, so about as decoupled as a separate domain?