You can expect a fresh install of WordPress on your local machine to be fast!
The HTML of a page should get downloaded within 0.1s (on a local machine)!
It turns out that I had an issue with the way my server and its configuration was set up, and the issue was not with WordPress at all. I’m posting the answer that I wish I had, because in my experience, a lot of WordPress sites are slow, and because of that, (and out of laziness TBH), I made the mistaken assumption that I just had to put up with a slow fresh install of WordPress on my local machine.