Most areas of our brain can only do 1 task at a time. If you try and do more, it flips rapidly between them. Basically, you would "watch" vaguely 30-50% of each show, with your brain trying to fill in the gaps.
Interestingly, you can do 2 tasks that don't share significant resources. This is how you can both drive a car and listen to a podcast. It's also why you suddenly need to turn down the music when you need to navigate, or park. Those require use of general cognition, which the music/podcast was using.
An interesting example of this is time keeping. Some people can talk and keep an accurate mental timer. However they will lose track when looking at images. Others will be the reverse, or something different.
It turns out that humans don't have a consistent time keeping mental circuit. We hijack other systems. If you "hear" the time passing, you will struggle to also hear someone talking without issues. If you visualise a clock, you can talk, but your visual cognition is now occupied.
