> My family goes hiking in Shenandoah in Virginia almost every year (probably 15 times in my life) and we don't reserve entry or trails or anything, and there's no lines.

I went to look up hikes in Shenandoah since this sounds like it could be part of a nice road trip with my family, and ironically I found that the most popular trailhead requires getting tickets through recreation.gov: https://www.nps.gov/shen/planyourvisit/faqs-oldrag.htm

So perhaps the problem is spreading?

Luckily it seems it's not nearly at "The Wave" levels of scarcity, you can actually get tickets on most days: https://www.recreation.gov/ticket/10088450/ticket/10088451