That's a valid argument against ever performing any dig whatsoever, since it's always true that future archeologists might have better technology to extract more information from anything you find.

Exactly right. This is a question that archaeologists are always supposed to ask before digging. If there's a justification for having the answer now (like an immediate research need or a threat to the site), then excavation may proceed. Even then, you excavate as little as you need as nondestructively as possible. Usually that'll be a single trench/pit you excavate with hand tools and re-cover when you're finished.

Most regions have databases full of known sites that are unexcavated because there's never been a justification for digging.

Knowledge for knowledge sake is not considered justification?

I suspect the missing bit of context here is that we have a lot more potential sites than that we have archaeologists with the time and budget to investigate all of them.

So in programmer terms, most potential sites never make it out of the priority queue

It might be, if you have infinite amounts of time and resources and expertise.

Catch-22: since future archaeologists have better technology, no digs are performed right now—thus archaeological technology is not needed, and there is no pressure to improve it.

I imagine the newer tech comes from outside archaeology

Radar, X-ray, that sort of thing

They had radar and geomagnetic mapping back in the 1990s, at least - Time team did ~250 digs that were broadcast on channel 4 and are now all on youtube, most in HD now.

And "geophysics" were used to decide what and where to dig in most of them. They're making new episodes now, as well.

https://www.youtube.com/c/TimeTeamClassics

They were examples of technology that came from outside of archaeology. I don't know what the future tech is called as I've not seen it yet :P

Compared to a fully equipped and financed archeology team from today, which is not the case. Those who discovered the site know they are underequipped and underfunded for the specific site. In this case, reburying is cheap and effective.

Correct. This is why like 99% of all known archeological sites is still unexcavated in parts of the world.

Thankfully, there is a suitable middle ground of extracting some reasonable amount of information now and preserving some of the site for later.