This is a great point! I've noticed a similar thing with Muir Woods in the San Francisco Bay Area. There are other amazing ancient redwood forests in several other places nearby (e.g. Samuel P. Taylor State Park, Redwood Regional Park, Joaquin Miller Park, the north side of Mount Tamalpais facing Fairfax, and several places along both sides of Skyline Drive along the peninsula -- probably among others that I don't know).
OK, the redwood trees in them might be only 80% as old and tall, the United Nations might not have been founded inside them, and some of them might have only 6 km of trails through the forest rather than 10 km. But many of these places are often nearly deserted, have no entrance fee, are a quicker and less twisty drive from San Francisco, and are incredibly majestic, peaceful, and spectacular.
Meanwhile, Muir Woods had to introduce a rationing and permit system to visit by private car or public bus (https://gomuirwoods.com/), and along the main trail on the valley floor you are basically never out of sight of other visitors during a weekend or holiday.
I've reserved a picnic area inside an ancient redwood grove for an upcoming birthday picnic.
https://www.yelp.com/biz/lake-lagunitas-fairfax
OK, it's definitely no Muir Woods, but it's just 6 km north of Muir Woods and you can reserve the area for a small fee on a weekend during the summertime.
I think the power-law effects you describe have been true of tourism forever. Muir Woods has attracted dramatically more tourists than the MMWD or EBMUD redwood groves for decades. But I also think you're right that the Internet is accelerating them, because you can hear about where to go via discovery mechanisms that so drastically and rapidly reward pre-existing popularity.
(If you live in or visit the Bay Area, check out https://www.marinwater.org/175/Directions-Maps-to-Watershed-... and https://www.ebmud.com/recreation/east-bay/east-bay-trails/ for information about hiking in -- often -- redwood forests owned by municipal water districts in reservoir watersheds, or https://www.marinwater.org/DocumentCenter/View/156/Map_Marin... for a map of all public lands in Marin County.)