My understanding is that it depends on how many services are offered at a particular business/building (think of how many different search results you might get for a single address on Google).
For example, Walmarts often have garden sections/entrances, a tire/lube section, etc. Each of these might pop up with their own contact information on a Google search. So in this case, I would put an area around the entire building and give it the top-level Walmart information. And then, pins for the Garden center, Tire center, Pharmacy, McDonalds, etc.
However if there’s a building that houses a single business/service, a pin is preferred I think. And then just a building area around the structure. For example, a Taco Bell would likely be in its own building, and they only provide one service / only one search result. So use a pin for the Taco Bell, and then draw a Building area around the structure.
And then when there are multiple businesses that are connected to each other, use pins for the businesses, and a Building area for the structure.