There are two thoughts here and I'm not sure I agree with either.
The proxy war with Russia has been running for almost a decade albeit that while we've been involved in the preparation for the fight, the West has done little in arming for it. It's not that there hasn't been an opportunity for it, it's just that we never took it. I'm concerned that Russia's performance to date may very well lull the West into a false sense of security , or, at least, a lack of a sense of urgency about preparing further.
The question about China is much more complex. Yes, we see it as a competitor and even a foe. What we don't see is the nature of the conflict. It has two key components: Taiwan - a conventional war in the old style - (which may or may not be accompanied by North Korea attacking south) and the artificial islands in the South China Sea. I'll leave aside the economic and cyber war that accompanies that.
China's actions are belligerent and part of a long game to dominate the area economically. That domination requires a stable but compliant world and not a war but there is little doubt that circumstances could arise where they take action - probably against Taiwan. The South China Sea islands importance is in simply being there. Tactically they may add a surveillance screen but are too small and too fixed to become major bases of operations. In a conflict they would be easy to neutralize. It's not like the Japanese occupying the western Pacific region with millions of men in hundreds of locations supported by large fleets.
In WW2, the Marines were the US's amphibious assault forces, but once a position was taken it was occupied by army and army air corps forces for consolidation. This island hopping campaign was necessary because of the limited range of weapon systems which couldn't reach Japan's mainland until a firm corridor was established. The navy cruised and cleared the waters in between the hops.
The Marines objectives for Force 2030 include "Force Design 2030 is our latest effort to adapt,
remain relevant, and out maneuver our adversaries." I think that means "not just be a small US Army". There is much debate within the Marines as to whether Force 2030 is the right move. Effectively they are designing a system of smaller forces that can seize and hold hard-points that the Navy can manoeuvre around and which the Army can subsequently occupy, if necessary, as the Marines move forward. The problem is numbers of men and ships. The region is vast, crowded and complex (for both us and the Chinese). Neither party has the depth to run a Japanese style Pacific War. Notwithstanding that, the war with China will be a long one. They have the initiative. It will probably unfold much like the war with Japan with initial loses that need to be retaken.
Which gets me back to the point that creating a mix of a light force (2 Div) and a heavy force (1 Div) constitutes exactly that, a Column A and a Column B to choose from. Organizing into those groups and enabling the ResF to be a mobilization base is the start of reform. The next, and costlier, phase is to purchase the right weapon systems to grow the capability. But you have to start somewhere and for us that's in organization and initially fixing the blatant capability deficiencies.