GAAP Devalues Real Estate?

Thank you guys so much for your responses to my last question. Here is another one: I read somewhere recently (I’m trying for the life of me to remember the source) that by GAAP standards, a company’s real estate is devalued every year. Isn’t this counterintuitive to how real estate works? Doesn’t real estate GENERALLY appreciate in value over time regardless of the type? (In this case commercial). As always, I appreciate your responses.