Does exporting at 1080p result in higher audio quality than exporting as a master file?

The original file:

I want to upload this file to youtube at the highest video and audio quality possible.

If I upload the file to youtube as it is it will be 480p.

Alternatively I could import the video into fcpx at 1080p 29.7fps and then export it at 1080p 29.7fps apple prores 422.

I would then have to compress the file using handbrake. These would be my settings:

So the bit rate would be 320kbps. The video codec would be H.264. The resolution would be 1080p. I would upload this file to youtube.

The video quality does not change regardless of whether it is 480p or 1080p?

However when the file is uploaded to youtube the bitrate is higher at 1080p than 480p?

Therefore it would be advantageous to carry out this process I described as opposed to uploading the original file?