Embedded goes into hardware, which is mostly a low-margin product. Whereas software products (be it FAANG or startups) either make a ton of money or are perceived by investors to have a potential to make a ton of money, so they can afford to spoil their devs. In the realm of non-product development, enterprise software can deliver milions/bilions in increased efficiency for the enterprise, so it's another field where there's enough money to spoil devs.
I think it's just a market failure where everyone already pays these wages, so no one goes out of their way to pay better. You can see this on the software side with China's "code peasants", or the UK salaries.
There's tons of in-house custom enterprise software development where, depending on the skills of the manager leading the project, the idea for the developed solution can be sold to upper management as the second coming of Christ (e.g. we'll spend $10m over two years on developers and potentially earn/save hundreds of millions) and this unlocks a pot of gold for the development budget. The manager will then want to hire good/expensive devs as this increases the chance that the team will deliver what he promised to the upper management. I've seen this multiple times in large organizations I've worked for.
It doesn't change the underlying equation.
https://www.payscale.com/research/UK/Job=Computer_Programmer...
What I'll say is that over $100k-ish at non-FAANG, the salaries say more about the company than the person doing the work.