No idea why they don't just stick one of the iPhone cameras in there. Heck, use the last gen camera. If the camera isn't too big for the iphone then it's not too big for a laptop- especially with the notch.
iPhone cameras are absurdly thick compare to the thickness of a laptop lid. If you've noticed, they've also gotten even thicker over the year (the camera bump has gotten thicker). Nobody will want a laptop lid as thick as their iPhone + camera bump.
Even the front (selfie) camera?
My iPhone 14 Pro is at least twice as thick (not counting bump) as the MacBook lid and the selfie camera is only 4k@30/1080@60. Not sure if there is a clever way to pack the camera or not but it doesn't sound good at first check.
Yeah. The back camera sits behind the screen whereas the front one pokes through it. I wouldn't be surprised if they were fairly even in terms of thickness.