Of course it is, a 1080p video at 10mbit will almost always look better than a 4k video at 1mbit, and a 4k video at 10mbit will almost always look better than a 1080p video at 1mbit.
The far more interesting question is if you accept you have Xmbit to play with, what is better on a given platform (screen size, resolution, viewing situation, how well compression works, how much battery is used in decoding, etc)
The far more interesting question is if you accept you have Xmbit to play with, what is better on a given platform (screen size, resolution, viewing situation, how well compression works, how much battery is used in decoding, etc)