Why don't they already then? Russia could shoot down satellites providing communications to Ukrainian drones for instance, couldn't they? I think it is because doing so triggers a large shitstorm and real geopolitical consequences, if it becomes the norm then no one will get to benefit from any satellites, so a smaller and less influential country is not getting off easy if they do that, same kind of deal as nukes and access to them except probably a little less so. The similarity being that there is a cutoff point below which no one has access, and above which heavy coercion and other manipulation can be imposed as an effective deterrent.