Projective power is not in decline though, and force projection takes many forms, for exaple the us prefers sea and air over ground force projection, while russia prefers ground and air force projection over sea, and china is kinda in the crossroads where they are not quite sure but given time they will figure out how they wish to use their military.
Manned aircraft are quite valuable fyi, drones can not replace them except for certain taks, and against a state actor drones can easily be jammed. Much of the push for drones is not because they are some super new tech, we actually were using them right after ww2 in testing, but rather that pilots are harder to obtain then aircraft. In ww2 you could quickly train a bunch of soldiers to fly piston pounders, they were simple in every respect, now you have sophisticated jet fighters, with sophisticated firing systems and tactics, this requires pilots to be more physically capable than ever to handle the gforce, and trained much longer as well for these new systems, which makes pilots in demand but short supply, anywhere drones can be used means we can keep pilots safe friom harm as well as recruit new ones who wish to fly without being in harms way.
However drones would fail quickly in a war against a sophisticated state actor unless they could act by ai alone and not need input which could be jammed.