The glory days of smart shopping have disappeared in 2022, but wait, you can set up a performance max campaign without any ad assets, which will only show shopping ads on Youtube, Web search and Display.
How cool is that!
This will allow you not to let Google automatically target Gmail, text ads and discovery. This means you can only target shopping ads or setup text ads separately in a different dedicated campaign.
All you have to do is create a performance max campaign without any assets or audience lists. Simply after you add your budget and bidding strategy, skip the asset creation and audience list by scrolling to the bottom and clicking on next, ignore the warning/error, and click on publish the campaign.