Oh, that's a nice approximation! Similar to Grace Hopper's famous demo of a six inch wire being about how far electrical signals travel in a nanosecond.

Wow it's insane how slow that is!

But also, I don't really have an intuition for why the speed of travel is relevant here?

It's funny that I have a natural intuition that sound is slow over long distances, yet 1 ft/s still feels astonishingly slow. And yet while I know light travels 1ft/ns, it's still astonishing that it takes 30ms to travel from London to Sydney at that speed.

sorry for late response

What I mean is that if you have multiple speakers around you, if any one is 1 foot closer or further than another, it'll be off by a millisecond already. Given that most people probably aren't going to have sub-foot positioning accuracy, sub-millisecond timing accuracy isn't critically important.