>People with family or basically any commitments outside of work don't have anywhere near as much time to practice for this sort of thing and why should they need to practice for an interview?

I've done this rodeo in my thirties and forties, complete with a very busy existing job, family, long commute, etc. The bottom line is that the time investment wasn't terribly large as it was more refreshing than learning things from scratch.

Putting the 20 hours in over a couple weeks for a 2x raise felt like a worthwhile expenditure of my free time, and worth prioritizing over some of my every day commitments.

Relative to going to med school, law school, or a top 10 business school, I can’t see how it’s not true even for those with families or commitments.

You go to med school or law school generally before you have had children. After you've done those things, you don't study for weeks leading up to an interview. Instead, you have a piece of paper that proves what you know and the interviews are more a decision of "do we want to work together" rather than "is this personal qualified".

I see, so among the audience which has been prescreened, life is good. I can see that being nice, if you're in that class of people.

However as someone without a CS degree who is nonetheless able to get jobs as a software engineer because there isn't a process of credentialing, I am glad much of the industry works the way it does.