Satellites are poor search tools
Satellites are just as bound by optics constraints as earthbound photographers, so the resolution of an image 20+ miles square is not at the centimeter level. High resolution zooms can be had, but cover a very small field, so the problem becomes telling the satellite where to look exactly.
Drifting debris beneath partial clouds need to be pinpointed by human interpreters, but will have moved by the time that is done. Consequently the searchers cannot direct the higher resolution images a satellite could take fast enough to do any good.
A real time satellite image analysis with immediate high resolution targeting might be available to the military, but none of the commercial earth observation satellites have that. Hence the 2-3 day lag between the taking of the satellite pictures and the public finding of possible debris.