Background
I am using Final Cut Pro X on a new M1 MacBook Pro (16gb of RAM) on AC power, and I have noticed that when I export the video project (share) the resulting video file is so much larger than what I would expect from my knowledge of the PNG photo format.
I created a "video" that is actually just my attempt to present a recorded phone call. So video quality doesn't matter. In the image below you can see that I created a static title card that lasted 60secs with an audio track (size 36mb) that lasts 30mins. I chose the export settings based on what I thought would be the fastest encoding and smallest video size. However encoding took 12mins and the resulting file size is 51mb.
Overall Question
What do I not understand about my chosen export settings and video codec that would cause such a large file size and a long time to export?
Secondary Questions
What settings should I have chosen instead?
Is there a specific codec that would be good to use when video doesn't matter in a video?