Justin Blanton:

Much of what makes this possible is that I can delegate in one way or another most of what I think of, and can get away with being extremely terse in my emails. At this stage of my career my day-to-day job requires minimal work-product; if I was coding all day, designing websites, or researching, I probably wouldn’t be able to leverage my pocket computer the way I do, but I wouldn’t want to either.

The more people you manage, in general, the less computing power you need. That’s not to say the iPhone 7 isn’t powerful — it is — but to point out that you don’t need all the niche tools on Macs in order to run entire parts of companies, hell to run entire companies even.