Not an oversight, it's a deliberate choice. Center Stage requires an ultra wide lens, which means distortion.
Think about how most MacBook Pro users will be using their computer. It won't be on a countertop or in the living room with multiple users. Unlike iPad, there is only one camera on the MacBook. If someone needs to show a document or other object, they want an accurate representation.
I'm not sure if you've used Center Stage — it doesn't sound like you have — but this isn't a significant issue.
The way that camera focal length works means that if you crop the image from the centre, there is no more distortion than if you'd simply used a more zoomed in lens. So for the scenario you describe, someone would generally be in front of the computer holding the document up, and it would show up just fine.
It is true that if you go to the very edges of the camera's range there will be some distortion, which the software mostly corrects.
Nobody puts their MacBook Pro on a kitchen counter like they do with an iPad. Center Stage is not a selling feature for MacBook Pro.
It's a selling feature for me.
It is a strange implication that people are only using their iPads on kitchen counters and so the feature must not work very well there. The feature works just fine when it's used at computer-like distances on a desk. If anything, it works
better because when the camera is closer it's harder to fit multiple people in should you want to do that. This isn't an uncommon requirement even in professional meetings, where multiple people are using a single laptop to dial in.
