> when you’re the nontechnical cofounder, your job is everything that’s nontechnical’ including grocery shopping and errand running. I don’t know why this comment struck me as odd

As a non-technical cofounder, this is the truth. I'm not sure what expectations at large are, but I can corroborate this story and believe it should be most 'non-technical' cofounders expectation of reality.

Take out trash, buy office furniture, go on sales calls, arrange the company insurance plan, order dinner on late nights, line up investor meetings, talk to users... I could literally go on forever - those are off the top of my head from last week.

Technical cofounders (and employees) should be maximizing their impact by doing technical aspects - other founders should be selling, marketing, building the business, and sometimes have to order food, clean up the office, or go see the company lawyers/ accountants/ & run errands.