The new stuff lures new subscribers. The binge-worthy shows drives retention. Disney has been smart with their purchase of Hulu/Fox and using those shows to provide a library of rewatchable content. But you are right, without new buzzworthy quality shows, your numbers will slowly shrink, and Disney has been terrible at creating good new shows (With the exception of She Hulk: Attorney at Law, obviously).

Netflix was smart to pour so much money into originals for like 10 solid years when investing money was cheap and that gave them a lot of runway to get a good library of originals and eventually become profitable in time for when money got expensive to borrow and investing dried up. Now they can fund themselves where everyone else is just bleeding and continue to afford a mix of originals to drive growth and binge-worthy shows to hold onto their current subscribers.