Short answer: it's not that we don't have the technology, its that we don't have a reason to. With very few exceptions, if you can do it on the moon you can do it on earth or in Earth orbit

Long answer: in the space industry/field the moon is incredibly boring, relatively expensive to get to, and adds an extra step of logistics to an already complicated mission profile. Most space related technology advancement efforts have gone into doing things in orbit and there is more to do there than on the moon, it's logistically simpler, and cost is orders of magnitude less. Stuff is still advancing there, think Hubble vs James Web, GPS 1 vs GPS 3, the entire GOES system. In terms of technical challenges, they're far more interesting than anything on the moon, but it's not as flashy/headline grabbing so it's not talked about much.

The US going to the moon in the 60/70s was a rare combination of a win for scientists, politicians, and the people. The political incentive went away since as the USSR space program collapsed so too did political pressure to continue to put men on the moon and "prove 'Murica is better than those damn commies".

In modern times the political incentive is returning with the continued efforts by China to do more stuff in space so we get the Artemis program, but the incentives aren't that strong which is why the program has moved so slowly.