It probably has a lot to do with China and Russia getting a bigger bang for the bucks.
Actually, as has been seen in the last two years in Ukraine as well as a great many conflicts since the 1970s, their equipment is largely marginal at best against the equipment of the West. That was seen in the multiple Arab-Israeli wars when they would take on up to a dozen other nations at once, all the way to the trouncing of Iraq twice. Iraq had the third largest military in the world and among the best aircraft and armor in the world in 1991, and were soundly defeated two times in a row (and at most fought a stalemate with Iran before that).
And despite claiming to have the best equipment and military in the world, they have been held at a stalemate in Ukraine for years now. And remember, when that conflict started they had the third largest military in the world while Ukraine had the sixth largest. In the over two years of conflict, Russia has lost over 3,000 tanks and over 600 aircraft which they also claimed were the best in the world. And if anything it has shown the world that their equipment is nowhere near as formidable as they had been claiming for over half a century. And this must be seriously taken into consideration when the vast majority of Chinese equipment is essentially a copy of Soviet and Russian designs.
There is an old saying, "You get what you paid for". And numbers can make a difference, but not unless there is a huge disparity between the two sides. Like in WWII, where Germany had less than 50,000 tanks. And was facing the Soviets with over 102,000 tanks and the US with over 86,000 tanks. Those two nations alone had Germany outnumbered by almost 4 to 1, that is the kind of disparity that Stalin was meaning when he quipped "Quantity has a quality all it's own". But when the numbers are not that overwhelming, quality starts to make a huge difference.
And once again, experience. Russia has not really fought a serious war against an opponent that was a serious threat since WWII. Mostly using their almost overwhelming force against nations that they already controlled and were actually nominal allies of theirs. Since the Korean War the only real conflict China had was against Vietnam in 1979. And of the three major powers (Russia, China, US), only the US has actual experience in naval operations. Neither Russia nor China has ever taken their Navy seriously, and it shows.
You talk about my being an "armchair quarterback". Then tell me what you can about the capabilities of the three nations when it comes to the sealift and airlift capabilities of the three nations. Or about fleet operations and UNREP. Ask any who is familiar with naval operations, and they will tell you how critical each of those is when it comes to naval capabilities. You got it wrong, you are the one trying to "armchair quarterback", because you really do not seem to understand what is important when it comes to a navy. And I bet if there ever was a conflict, they would both get trounced. Primarily because they lack any real experience using their ships as a navy, and would be unable to keep them supplied and operational. Both of them have had ships that never saw combat that spend years or decades at the wharf and almost never put out to sea. The US on the other hand has had ships that were severely damaged returned to port, repaired, then sent back to the fleet and continue to serve for another decade or more.
Such as the USS Samuel B. Roberts FFG-58. A Perry class Frigate damaged in the Persian Gulf when she struck a mine in 1988. Most of the world simply assumed she was a total loss because the keep was broken and both engines were destroyed. But she was returned to the US, and after 16 months returned to service and served for an additional 26 years until she was finally retired in 2015. You also have the USS Stark FFG-31 and sister ship to the Roberts, which was hit by two anti-ship missiles in 1987. It was also believed to have been a total loss, but was back in service a year later and served another 11 years until retired in 1999.
And those were both frigates, at just over 4,000 tons considerably smaller than the Slava class Cruiser Moskva at over 9,000 tons. And many believe the poor damage control is the main reason why the Moskva was lost, a problem that has plagued the Russian Navy since the Russo-Japanese War over over a century ago.
