Simple summary of the differences: $AST SpaceMobile(ASTS.US)

Starlink's advantages (mid-band + massive constellation scale): High capacity, relatively high speed, suitable for scenarios like "wanting to get online in the wild, transmit videos, use apps." It may become a major player in "global mobile broadband" in the future.

ASTS's advantages (low-band + carrier spectrum): Better penetration, more reliable indoor/deep coverage, suitable as a supplement for "remote mountainous areas, inside buildings, emergency connections during disasters."

Neither is an "all-round king." The FCC also deliberately allocates spectrum to different players to avoid interference, allowing the market to form a hybrid network of "ground 5G + different satellite supplements."

From the perspective of my personal needs, I feel that Starlink's offerings better match my actual needs. Of course, one must also consider the practical situations of large markets like the US/China/Europe, including Africa, where infrastructure is a complete mess;