When you say commercial real estate, that covers a whole lot of territory. Retail, hotels, industrial, office, public storage, mixed use, high rise, free standing. The market is different in each one of them. The ups and downs in each move on their own tracks (somewhat like high end and low end residential, though there is at least one of those categories that has continued to perform very well over the last few years.) The current investment model is different in each one of them. The financing is not always the same either.
In most categories,(though not all) trends tend to follow residential rather than lead. With the exception of hotels, trends tend evolve slowly, both up and down.
Comparing commercial real estate to residential real estate is like comparing apples to fish. They’re not even in the same family. And when someone tells you that commercial real estate is “mostly” anything, they don’t know what they’re talking about.