On mobile, scrolling down the screen seems both easier and more common for most users. I have not seen the research as to scroll depth. Regardless because the screen is smaller and the opportunity to find the answer is less, many folks don’t hesitate on mobile results.
Google, more and more, seems to want users to leave less (travel planning, AMP & Google Posts) or to leave only with an actionable behavior that Google can measure (like click to call, book a hotel, make an appointment).
So this minor upgrade, adding the eye candy of visuals from the “People Also Search For” feature to the bottom of the mobile search results on a brand or One Box search result makes sense. It allows folks to scroll through other local businesses just in case and to hopefully find one that they can click on. This feature has always been available (and remains so) in the Knowledge Panel for a business on both desktop and mobile.
The bottom line for small businesses? Make sure that the profile photo that Google is using looks great!
Google Updates Mobile Branded Search with People Also Search For Option by Mike Blumenthal