Here is why I think it would work:
Also, Most video have a ratio that is wider than the phone in landscape.
I think you may be a bit behind on how large the notch is on new phones. It’s literally just the front camera hole on new phones, including Galaxy, Pixel, and iPhones. I’m fairly certain that’s also the case with the majority of other Android manufacturers such as OnePlus, but I can’t be bothered to check.
iPhone is pill shaped. Regardless as long as there is a space with the ratio of 16:9 in the center it doesn’t matter the shape of the edges. It would give you more real estate on the screen when doing other things than watching videos, plus the corners are not even touch friendly when held vertical.
An oval shaped phone is simply far more impractical than a rectangular one. Sure, the far corners are a pain if you need to use it one handed, but that’s a significant amount of screen space you’re giving away for simply browsing things.
So sure, if you do literally nothing but consume video content on your phone, fine it could work. But who does that
The videos would be smaller, or the phone would have to be huge. I can already multitask on my phone, an oval shaped phone would be incredibly impractical. A notch/cutout isn’t a big deal, it just sits in the notification bar and phones didnt even used to have screen there anyway.
Phones getting too big is why they are harder to use one handed, not because they are rectangular.
