Really? I don't think that's why Arch is well known. If you gave me just that description I'd be very confident you meant Gentoo.

In my mind, Arch's reputation is not that of a challenge, but more of an ongoing projects that you can soak up as over much time you'd like to dump into it. Basically the OS equivalent of a daily-drivable project car.

Though to be fair, I think one of the pillars of that reputation is the quality of the wiki. And I've been increasingly finding the wiki not living up to my expectations over the last however many years. But (somewhat concerningly) the Arch wiki seems to be as strong as ever relative to other sources, so I'm not sure how that balances out.

Maybe it doesn't, and I'm just behind the times.