Flying is expensive no matter where you’re going. And hotels can be a big expense, too, no matter where you go. I consistently have paid more to stay near a popular national park like Zion or Yosemite than I have to stay near Disneyland.
Tickets to Disneyland aren’t a “small part” of the vacation expense, because in my opinion, Disneyland is the vacation. I can spend five days there. Whereas in Branson, we had to do random different activities every day to fill up our trip, and the cost added up. Theme park tickets were definitely a smaller portion of that trip, but just because there was more variety and a nicer hotel, I wouldn’t necessarily say it was a better “value” as a vacation. I greatly value the original Disneyland, as do a lot of other people. If the price was too low, it would be even more crowded.