Using Uber as the example if I turn off Lock Screen notifications and turn on time sensitive notifications then will I get no marketing notifications, and only notifications about my driver turning up?
It's up to the app developer, they get to mark notifications as time sensitive or not. So if someone decides that because a coupon is expiring soon it's "time sensitive" to ping you about it, then they can mark it as such. Hypothetically Apple could frown on this in app review, but it isn't something app reviewers are likely to be able to reliably catch.
Uber eats though, I can never seem to get right, and it tries to spam a lot more. So I still agree with the original point