This is similar to people being surprised by the typical age of civilian general aviation aircraft. Dozens of types from the 40s, 50s, and 60s are still flying great, which is what meticulous maintenance and logging gets you. Visit Alaska and you’ll spot loads of Cubs from the early 1940s. It’s not uncommon to train in an aircraft like a Cessna 150 or 152, and a lot of those predate the Moon landing. You can buy a nice aircraft from that era, one which will last you a long time with (expensive) care, for about the same cost as a Prius.

One can get a lot of mileage out of something designed to be airworthy and reliable and maintained by a careful lineage of owners.

Argentina is an amazing place who level of screwed-upness is tragic.

Argentina has 2 distinct effects. The first is that after the dictatorship in the 70's, the military has been systematically defunded. Any politician that needs a buck, and they all do, will always put the military last. Its a front-pager for the government to buy a new military plane: it costs votes and money.

And second, we have a level of systematic corruption that has eroded many institutions, including the military. Noticeable so, the state of military aircraft is in shambles and many army people died because the funds for maintenance where stolen. A famous documentary by a former pilot details these issues.

In fact, the Ohio itself, launched in 1979 is still in active service.