The idea that "there is no comparison" between FAANG compensation and the Cravath scale is a bit strange. Looking at Cravath's figures, a fresh grad can expect to make 212.5k in their first year. This is close to the top end of what a fresh CS grad can squeeze out, at least on an annualized basis; if you add in sign-on bonuses, FAANG comes out ahead (e.g Facebook gives its top-performing interns 100k sign-ons if they decide to join when they graduate). At least at Google and Facebook, stock grants over a certain size vest monthly with no 1-year cliff (and nearly all engineers will have stock grants sufficiently large to hit that condition), so the RSUs are significantly de-risked. Amazon gives you a comparable "sign-on" bonus in cash which also vests monthly for your first two years (to compensate for the back-loaded equity grant).

Another question is if you joined a FAANG in 2013 and stuck around until now (or hopped between FAANGs), would your pay have kept up? Trivially speaking, yes. A stock refresher you got 4 years ago would have gone up:
2x for FB
2.5x for Google
4x for Amazon

You would easily be making 450-500k as a senior engineer with appreciated equity (or, you know, making that in cash at Netflix).

If you joined Facebook in 2012/2013 and stuck around there's a very decent chance you'd be a Staff engineer now, not Senior, and making closer to 600-700k/yr.

This is all ignoring the fact that you didn't need to spend 3 years and tens or hundreds of thousands of dollars on law school, which actually understates the opportunity cost, since an engineer joining FAANG will be at least 3 years ahead of a corresponding lawyer on their career track (including raises/promos/appreciated equity), so the more fair comparison would be to an engineer who joined in 2009/2010, which tilts it even further in favor of the engineer.

Entirely apart from all that, I find the question of whether engineers are "appropriately paid" a bit confused. There may simply not be enough engineers with the correct skills/talent/etc (whatever FAANG is looking for) at any price to fill all their open headcount, so increasing compensation would be a zero-sum game (for the companies, obviously).

I think the more boring truth is a combination of a few factors:
1) engineering at that level is actually sufficiently difficult that most people (when considering the entire population) can't do it
2) most people don't know what engineering pays - even outside of FAANG, hitting 6-figures in most major metro areas is pretty trivial
3) most people don't optimize their life/career to any appreciable degree, so even if they did know, they still wouldn't be particularly motivated to get into software (you'd see a lot of people saying that they're not smart/talented/whatever enough, which would be true for some of them, but the claim would mostly be driven by rationalization, not from any actual evidence they have)

To use myself as an example, I started out as an engineer making under 50k/yr (in a minor tech hub in the US, not the Bay Area/NYC/Seattle). Outside of talking to my parents, both of whom are in the field (though both slightly adjacent to the central conception of "software engineering" on HN), I had no idea what the market looked like. Maybe a year or two later I met someone who worked at a reasonably well-paying tech company (though not quite at FAANG levels) making ~200k/yr, which I hadn't even realized was possible. They told me I could be making that kind of money in a few years if I studied & interviewed at the right places. I didn't really believe them. Fast-forward a couple more years: I'm wasting my time in a (different) dead-end software job, making not-quite 6-figures, doing maybe 5-10 hours of work a week. I stumble across Dan Luu's blog and patio11's article on negotiation in quick succession, which light a fire under me. Six months later I'm working at a startup for a bit under 150k/yr. Six months after that (it was not the best place to work) I'm working at a (non-FAANG) tech company making a bit under 300k/yr. I've been there for a bit over two years now and my current annualized comp is over 500k at current stock prices. None of this is terribly unusual; anyone who joined FAANG a couple years ago has seen nearly as much stock growth (and better secondary benefits). If you joined Snapchat a couple years ago as a Senior eng, well, you'll probably be set for retirement by the time your 4-year grant runs out.