“And all of them are reasonably easy to thwart if you know their orbits and keep tabs on when they are ‘looking’”
And those same EMCON conditions are just as easy to implement when a balloon is overhead.
Those EMCON (and other measures) were taken as the Chinese balloon flew over. So, little or no new data was collected.
However, the F-22 missile shoot was a gold mine of data. It’s not very often that an adversary gives you front row seats to a missile-ex. And to have your SIGINT collection device the target:priceless.