since you're in the field, what could be the cause of the "lack of progress" ? We need detector that are too hard to build to get the data/measurements we need to progress ? Or do we lack a sort of "flash" when someone figures the new physics out of the current knowledge by a change of point of view ?
Not parent, but the cause is obvious to everybody in the field: existing fundamental theory (general relativity from 1915 and Standard Model, completed by the mid-70s) while manifestly incomplete, is consistent with all available experimental data.
New accelerator experiments capable of pushing significantly beyond the explored energy range would take a decade+ to build and cost tens of billions (and up), and there is no guarantee that they would find anything new.
