> but showing the whole action from a roof-top or sky camera or atleast traditional football broadcast like camera would make it more watchable

I'm quite sure this is very intentional with Rocket League broadcasts. There's even a "director cam" that Psyonix built for this purpose, and it is still used often. It's just that it's not as exciting or impressive when you're not seeing it from the player's view for whatever reason. Everything looks slower and you miss all the nuances of the pros' mechanics.