In Yellowstone, as long as it is not a seismically active area it’s not off limits and you can go there. Most people just stick to the roads and just miss out on what Yellowstone can be like.

There's some truth to what you said. But that doesn't explain why Denali is in the 40s. There's only one road in the whole park, and no private vehicles are allowed. You can get off the park bus and after it drives off you are completely by yourself in the wild. Not just any wilderness; it is majestic. The park is larger than Massachusetts.

Yes it's very touristy, but it's that way for a reason - because it's amazing. The combination wildlife, variety, and geological features are just unmatched. It's not like it's impossible to get away from the crowds, either.

Also another fun fact about Yellowstone (kind of) - the valley through Idaho to the southwest of Yellowstone is there because of previous super-volcano eruptions, of which Yellowstone is simply the latest. As the continent is pushed further west, but the hotspot that formed yellowstone stays in place, there will be another super-volcano do the east of yellowstone.

One of the things I love most about nature is seeing the evidence of millions of years of Earth's history, and Yellowstone is chock-full of that. I don't know if there are better examples of plate tectonics in the entire world.

Growing up in the northwest this was 100% my opinion going through Yellowstone. The thing that makes Yellowstone cool is the animals, there are much better viewing experiences in other parks. But seeing herds of bison, or bears and wolves is incredible at Yellowstone. Grand Teton on the other hand felt undersold with its beautiful vistas and lack of traffic.