I mean yeah, ultimately its down to the individual on how they consume content and if they are happy to do it sped up then that's fine for them.
For me though, especially with films/TV, it's not possible to fully appreciate how it is structured or the impact that the various decisions made in how it is presented if its sped up. Imagine a scene where there is a lull intended to create tension and its been designed to last to the perfect moment. Now imagine watching it sped up and it has now lost all of the dramatic impact because the scene wasnt allowed to go at its intended flow.
You can in that moment understand from a functional perspective of what that scene was meant to convey, but you dont get to actually experience it for yourself.
Same thing could be said for comedy, timing is everything so to change that timing would change the impact of the joke.