To be clear, Disney is pulling the content from existing monetizations -- including Netflix -- to try to monetize it on their own platforms. This isn't free real estate. There is a very real cost.
And Netflix is going to put the money they aren't paying Disney to produce their own content and buy up other content.
Disney is playing a very risky gambit here.
Disney+ can be a fantastic success if Disney gets it right, because they do have lots of excellent content. But if they don't take the engineering side seriously, it's going to fail.
If Disney just wanted to focus on making good movies and TV shows, which clearly is what they're best at, dealing with Netflix would have been perfect for them. If they want to be a tech company instead, they really need to follow through and commit to that.
Disney has way deeper pockets than Netflix, they can afford to play the long game, spending their revenue on gaining market shares.
They already do that.