That may be true with current space vehicles, but there’s no fundamental reason that two or more SVs can’t form a distributed phased array (for MIMO a la WiFi). At least from a physics / spectrum perspective. The engineering might be tricky.
With SVs separated by hundreds of km, the beam width would be absolutely tiny, and channel reuse would be effectively infinite.
With SVs separated by hundreds of km, the beam width would be absolutely tiny, and channel reuse would be effectively infinite.