High-energy physics is kind of stuck on that. Most of the interesting questions involve energies or distances way beyond what's reachable by experiment today.
Meanwhile, there's interesting experimental action in low-energy physics, down near absolute zero. Many of the weirder predictions of quantum mechanics have now been observed directly. Look at the list of Nobel laureates in physics since 1990. A big fraction of them involve experiments with very low energy states, where thermal noise is small enough that quantum effects dominate. Some of that work led to useful technology. That's forward progress.
> Most of the interesting questions involve energies or distances way beyond what's reachable by experiment today.
Astronomers can observe extremely energetic environments from a great distance.
It's not a controlled experiment, but sometimes they get lucky and see something that suggests new physics.
I have no idea what might be needed to provide astronomical evidence for string theory.
Kind of interesting to think about how the scale (range or magnitude) in which we are able to detect something has such striking implications for the model that gets developed based on these findings.
Even when we are able to operate at higher resolution sometimes the model makers still operate on their own scales. For example, I believe political science and economics ought to be studied from a biological perspective if they are to be fully understood, since gene by environment interaction determines so much. However, there seems to be little interest among political scientists and economists to study the nitty gritty of molecular and population genetics, and little interest among the molecular and population geneticists to study political science and economic theory. And because of this, seems to me such models will always fall short compared to models that operated on a perhaps more appropriate scale of inputs.