I'm a former embedded software guy and I can explain a bit more. Hardware is extremely capital intensive, takes a long time for any return, and the margins tend to be pretty mediocre. Around the mid-2000s many embedded developers wound up getting siphoned off into mobile development (back to around Symbian times) which was far higher up the stack than doing anything with micro controllers, RTOS, etc. The embedded software community is mostly a bunch of electrical engineers that learned software second and this can be a small handicap against pure software people that learned hardware far later. Absolutely there are still great engineers doing embedded work in the US, but it's a shrinking market in a lot of ways and very regionally concentrated (not just _any_ metro area will do for stable employment - places in Texas or outside Boston were dominant).

I left embedded dev because I saw this coming and I'm just a slow developer that wouldn't have cut it with the demands of mobile software emphasizing cranking out stuff faster when that's just not how I work.