Concurrency is very hard for humans to get right. It can work in a factory where we can analysis everything and figure out that someone has time to do two jobs (you might be able to put the windshield wipers on at the end of the line and then turn to a different line to put the seat recline buttons on - if the lines are arranged for this and the bottleneck is somewhere else on the line). However most home jobs are not the repetitive and so you can never get good enough at something to take advantage of it. (maybe if you always make the same meal every night you will know where the breaks are and can do something else - but most people like more variety in life)

Absolutely!

And even this is a challenge!

We just weren’t built for doing more than one thing at a time out of the gate, and context switching is our achilles heal. (Not to say there aren’t extraordinary examples to the contrary, its just not the default and requires a lot of practice. I’m thinking specifically about musicians but most people aren’t ready for the kind of commitment necessary to reinforce the neural pathways required to develop the skill)

You hit on something really deep about variety. A conversation near and dear to my heart, sadly this forum is not really conducive to the kind of long form dialog the topic is deserving of.