If that's the case, then why does Apple not collect 15% or 30% from McDonald's, Walmart, Starbucks, Amazon, Target, Uber, etc. for every transaction made through their respective apps?
Again, per https://developer.apple.com/programs, the $99/yr that Netflix and every other develop pays Apple covers those costs.
In case you didn't read it the first time:
Join the Apple Developer Program to reach customers around the world on the App Store for iPhone, iPad, Mac, Apple Watch, and Apple TV. Membership includes all the tools, resources, and support you need to develop and distribute apps, including access to beta software, app services, testing tools, app analytics, and more.
I asked you before and you didn't give an answer, so I'll ask again, what other costs are there that the $99/yr developer fee doesn't cover?
Better yet, let me put the question this way: What costs is Apple incurring from the Netflix app, but that Apple is not incurring from apps by McDonald's, Walmart, Starbucks, Amazon, Target, or Uber, to the point where Apple needs to take a 15% cut of Netflix's app revenue, but not from the others I mentioned?
Bingo.