First park tickets are just part of the story they are also adjusting hotel room costs and occasionally offering ‘free’ meal plans. Those prices go up and down not just for the specific day, but also how far out your doing the booking. On top of that they do various partnerships and large group discounts to try and keep the parks filled.
That's DisneyWorld, not DisneyLand. They have an entirely different pricing structure because they have so much more space there, they can just build more park to meet demand. So they are built to the peak and then need to incentivize people to come off peak.
DisneyLand can't build any more park, so they could charge even more than they do now and keep the park full.
Ahh ok, I see where you’re coming from though Disneyland has a similar list https://disneyland.disney.go.com/events-tours/ and pricing structures. That park is apparently more dependent on locals.
Most of these are either seasonal events or have prices that shift in response to time of year or just demand. https://disneyworld.disney.go.com/events-tours/