I don’t entirely agree. AFAIK, there has never been a period (until recently) when drills were standing idle because they didn’t have a good location in which to drill.
Now, it’s probable that some federal lands out west were better sites than some drilled on private land east of the Mississippi.
But to my mind a drilling company would have to be idiotic to pursue drilling on federal lands, with regulations and enforcement subject to change with each election, in preference to drilling on private land subject primarily to state regulations.
IOW, the reason more wells haven’t been drilled is due to limiting factors. I believe those have been primarily trained personnel and to a lesser extent number of rigs. I don’t think lack of drilling sites has generally been one.