I'd like your detailed analysis on this.
Since this is WDW forum, let's stick to Orlando parks.
Since Disney grew every Orlando park, this implies the pie is getting larger.
I realize Disney has 4 parks in Orlando and Universal has 2, but Disney still grew more total guests than Universal. I'd argue Disney parks are more at "capacity" than Universal's parks. Growth rates at Disney parks slow down by the law of large numbers and the fact Disney has failed to expand adequately (I'll get to this later). Let's look at raw attendance numbers
IOA: Flat
Universal Studios in Orlando: +1,200,000 (very nice gain)
MK: 4% Growth +750,000 guests
EPCOT: 2% Growth +225,000 guests
HS: 2% Growth +204,000 guests
AK: 2% Growth +202,000 guests
Total WDW Theme park guests added: +1,375,000*
*Numbers rounded
WDW still added about 175,000 more total guests. Yes, more parks, but that's a Disney advantage. If you consider their market position as the decided leader, the fact they're even competing in total guests added speaks to their utter market dominance, particularly in Orlando.
You have to understand, growth rates are much more difficult with larger numbers and the bottom line is always butts in the park, which has Disney still winning in Orlando. Let me give you an example about growth rates. If I have a stock portfolio worth $100,000 and yours is worth $1,000,000, I might want to talk % gains. What really matters in the end? Dollars. I can boast all day about a 30% gain in my portfolio, but mine is still only worth $130,000. If you make a solid 15%, yours would be worth $1,150,000. You made $150,000 and I made $30,000. Who is winning? I had twice the growth rate, but you made 5 times more money.
To say Universal took a percentage away from Disney is quite misleading. Universal had a nice gain on a larger pie with better growth rate, but I just showed you Disney actually hurt Universal more than Universal hurt Disney in Orlando by adding more total guests. Perhaps Disney should have taken even more of the "new" travelers piece of the pie, but I don't think they're worried in Orlando yet. We can talk percentages, growth rates, and other second place math all you want, but Disney is still adding more total guests to its parks in Orlando despite being at capacity.
Disney's attendance domination is even more impressive when one considers fact Disney has literally allowed 3/4 parks to nearly die and still grew attendance and guest spend at all 4 parks.
Frankly, I was shocked Disney added more guests. I thought AK, EPCOT, and HS would NO WAY have any growth at all. The state of those parks should be negative growth, but Disney's dominance is too strong.
Once Disney world adds more themed lands and expands further, you will see attendance growth accelerate and the gap will widen even more. These numbers certainly don't make Disney feel rushed to expand...which we can all plainly see. They are in no hurry and they don't need to be.