Yes, but students need to buy textbooks. Is it really for "the best" if students have to worry about paying hundreds of dollars for the latest version of a textbook rather than getting 99% of the benefit from the PDF for edition n-1 they can find online?

> Plus its a petty injustice that only hurts people in aggregate, and it only hurts people who already can afford college in rich places, so no-one is really going to care about this to change it.

No, no, and no :(

No, that's not it at all. Calculus 17th edition is not in any way better than Calculus 16th edition. If anything, the newer one has more typos, weighs more, and is more expensive. A 600-page single-variable calculus text does not help students learn the material, since the small number of wonderful ideas that make up calculus are diluted in a fetid sea of repetitive examples, mindless busywork, pointless "real-world applications" that have no relevance to the real world, and a general tendency to give recipes that guarantee you will get the right answer even if you have no idea what you are doing. That's not math. That's the opposite of math.

New interventions often aren’t tested head to head against their alternatives. Or inadequately tested against them.

So we have no idea if they’re even better, but manufacturers don’t want to risk the embarrassment of evidence that they’re inferior.

The next day I had a severe allergic reaction to it, and the dentist replaced that prescription with plain old penicillin (which cost me $10 for the complete treatment). I was absolutely furious that he didn't go with the affordable and time-tested treatment first.

But surely what's best for patients is the treatment with the best cost/benefit ratio, not necessarily the treatment that is marginally more effective but much more expensive.