Went to Yosemite two weeks ago. The area around the visitor center is indeed packed full. Looked more like a city downtown, rather than a park.
The rest of the park though? Crossed the park via the Tioga Pass to reach Mammoth Lakes (which is outside of the park). There was very low traffic and a handful of people.
I feel that most people are concentrated in a few areas only, which should help. But the park is MASSIVE (takes almost 3h across by car). The entrance fee is a bargain considering how beautiful it is, and the sheer size of the area that has to be maintained and patrolled.
Grand Canyon of the Tuolumne for victory. I dont live or work in CA, but have hiked it and it’s known amongst backcountry employees to be the “secret,” best route in the park.
Only mention it here because the sheer Kantian sublime will keep the hordes out ;)
Careful of the rattlesnakes back there. I almost got bit once when I was deep in the backcountry, and I would NOT want to be forced to find out what it takes to endure that situation
To be fair, Tuolumne and the Tioga Road are already in their off-season where no overnight parking or camping is allowed and all services are closed. Anyone up there has to be on a day trip, unless they have a wilderness permit and either packed in a long distance or had someone drop them at a trailhead up there. During the summer months, Tioga Road can be clogged like an amusement park too.
Also, while there is an entrance fee that applies per vehicle and gives you access for 7 days, there is also an NPS annual pass which costs about $100 and lets you enter every National Park and National Monument. So, you never have to pay more than approximately three Yosemite entrance fees in a single year, no matter how often you visit.
When I was a kid, we also had a "Golden Eagle" pass which combined the NPS annual pass with similar unlimited access to all California State Parks. I haven't seen that option in a long time though.
Acadia is relatively tiny compared to the western parks. Still possible to get off the beaten path, although it's more like a public summer retreat than wilderness area.
The glitterati Parks like Yosemite, Yellowstone, or Zion are overrun. It’s a difficult situation compounded by lack of budget for staff and upkeep.