I used to spend so many off-work hours on my custom printf functions to try so desperately to find optimizations to save on space. I got it down to, IIRC, ~1300 bytes on a PIC8 and ~1500 on an MSP430. I left embedded because the pay:work ratio was shit (compared to backend / web development) but damn do I ever miss that work.
In terms of pay/work ratio, it might always hold true that it trends lower for embedded work. For individuals, though, I think the variation is a lot higher.
In my personal experience, there's a huge demand for experienced embedded software engineers in the bay area, and companies are willing to pay competitively. The team at my current company has grown from just me to a dozen embedded engineers, and we have several open positions for more. When I worked at Google, I'm pretty sure the embedded software folk had above average total compensation compared to general software engineers.
I think a big part of it, though, is that embedded engineers in silicon valley tend to get pulled into longer term high capital expense projects. The compensation packages tend to be more equity than salary, and so the salary component is below average. You need to be willing to take the risk to get the upside.
From what I hear from friends in the midwest, the compensation is significantly lower than the difference in cost of living, which is unfortunate. Salaries may be above average, but without much if any equity.
Another part of it, I think, is the sheer amount of interdisciplinary and domain specific knowledge required to be a truly strong embedded software engineer. The demand curve is very heavily biased toward senior level engineers. The companies with the money to spend want the best, and with such high capital expenditure projects, they can't really afford not to.
I don't think it ever held as a fact, it's really dependent on location.
If you compare web developer at FAANG to a random embedded developer, of course embedded is a joke. (A better comparison might be workers at Intel/AMD and I don't think they are terribly treated).
If you compare jobs in another city/country, maybe a city that has a bit of defense or aerospace industry, embedded is not necessarily that bad compared to other tech jobs available.
