Fundamentally, the US military is optimized for quality over quantity.
Look at the US Navy: ~400,000 active duty personnel operating ~400 ships (~250 combat, ~150 aux).
Compare to the Chinese PLAN: ~250,000 active duty personnel operating ~750 ships (~500 combat, ~250 aux).
A huge portion of that difference is due to aircraft carriers (11 USN, 2 PLAN), average tonnage per ship, and specifically the USN's lack of frigates.
This arrangement optimizes for the USN's mission of international power projection, where logistics requirements are like an iceberg, with the deployed forces being the above water volume.
However, it does leave a problem of training and experience. If no numerous smaller vessels exist for SWOs and crew to come up through, how do we expect them to have a deep reservoir of experience by the time they're commanding and crewing a destroyer+?
The retirement of the Perry class, subsequent botching of the LCS program (and finally recent selection of a Constellation class design, to be built) left the current USN with ~50 less commands for officers and crew to cut their teeth on.
And the personnel issue goes deeper than that. Recruitment is seeing some negative trends. You need a lot of people to man the ships. There aren't a ton of people interested in that. Reducing crew numbers was a major consideration in the newer ship designs.
But there is also automation that helps with a lot of tasks that are no longer required to be done manually. I don't have any expertise in ships, but I can give the example of airline aircrafts: 50 years ago you had 4 people in the cockpit (pilot, copilot, navigator, mechanic), then 3 and now just 2 (pilot + copilot) and some companies are toying with the idea (that I don't like at all) to reduce to a single person. From 4 to 2 or from 4 to 1 is possible due to automation. I think it is similar with ships.
One responder replied with one possible reason, I will give another based off my time on a rather new LHD. The Navy, to cut cost on construction, uses a lot of hand-me downs. I believe if I remember correctly, some of our engineering gear was repurposed from the USS Kitty Hawk. I dealt specifically with aviation fuels, while carriers often have limitorque values (think automated if unfamiliar), the ship I was on had none, all valves in the Av fuels system was manually operated. Keep in mind, I think construction completed in 2009 (so limitorques were definitely around).
Look at the US Navy: ~400,000 active duty personnel operating ~400 ships (~250 combat, ~150 aux).
Compare to the Chinese PLAN: ~250,000 active duty personnel operating ~750 ships (~500 combat, ~250 aux).
A huge portion of that difference is due to aircraft carriers (11 USN, 2 PLAN), average tonnage per ship, and specifically the USN's lack of frigates.
This arrangement optimizes for the USN's mission of international power projection, where logistics requirements are like an iceberg, with the deployed forces being the above water volume.
However, it does leave a problem of training and experience. If no numerous smaller vessels exist for SWOs and crew to come up through, how do we expect them to have a deep reservoir of experience by the time they're commanding and crewing a destroyer+?
The retirement of the Perry class, subsequent botching of the LCS program (and finally recent selection of a Constellation class design, to be built) left the current USN with ~50 less commands for officers and crew to cut their teeth on.