You can do different things at the same time, yet chances are none of them will turn out to be done particularly well.
Sure you can do the dishes while talking to the kids, or prepare food while talking on the phone, or drive while listening to a podcast. You’ll be a lot more tired in the end, but for basic and repetive actions, stuff our body does basically automatically, it is possible to add something else on top.
Try though doing the dishes while your son is talking to you about a deep matter that bothers him; or impress your family with a totally new recipe while your mother is guiding you through the schedule for her next visit; or navigate the streets of a neighborhood you have never been to before while the music is on.
In those cases you’ll have to tune something down, possibly stop doing it completely. It’s exactly when you are doing important work that multitasking becomes a myth.
If you are working on a report to present during the next board meeting, and you also answer a bunch of e-mails you’ve received in the meantime, send a text to your wife to say you’ll be late, and get back to your colleague on Slack, most likely some of that greatly suffered in quality (I bet it was the report).
Work as if you are not the 2%, and allocate enough time for things that deserve your full attention. Do not get distracted, be brutal when needed, and you’ll finish faster and have time for the rest.