Yep, this comment does a good job of illustrating the (surprising) complexity of this.

I'll add that the notion of the "time scale" variable as mentioned in the article is something that's only solidified/codified since Unity and the like came about. And at the same time, the way Unity et al. works[0] doesn't really encourage thinking about what I'd call "main loop logic" in the bottom-up way that's required to build a really robust system for managing states. You can do it, of course, (you can write as much code as you want) but by default, everything in the scene is "active" and somewhat independent from everything else, and you don't have direct control over the various major systems.

[0] I guess I should say "worked" -- I mostly used 3.x and a little bit of early version 4 -- I'm sure it's improved but I wouldn't expect anything drastically different.