Its a well known dirty secret that consulates of all countries serve double duty as offices for foreign intelligence services. The two possibilities I see are either the US had intelligence of some particularly egregious use of this not-so-secret arrangement or the current administration has just taken an unthinkable sledgehammer to a serious diplomatic norm just to be "tough on china". The fact that biden is polling well in Texas and Trump's whole schtick in his ads is "Biden won't be hard on China", it seems likely to me that this whole thing is a reckless campaign stunt.

While the Houston fire department did show up, they respected Chinese sovereignty. In other words they did what a fire Dept is supposed to do for embassy calls, and the calls were not unfounded. The only other case I know of a consulate burning everything was the Soviets at the height of the Cuban missile crisis.