This is horseshit.
The bulk of the embedded developers right now are aging boomers who are soon to be exiting the workforce. I barely know anyone else my age who does this stuff.
Yes the ecosystem is changing. There's been a "recent" movement towards ARM-all-the-things, even the little bit-banging chips that everyone is talking about. You can get uCs with clock rates from the single digit MHz all the way to GHz with loads of features. Most people seem to be running an RTOS on top of anything over a few Mhz but there are a few of us who do things the hard way when things get tight.
That's just the uC stuff though. There's so much more going on in the industry. Someone needs to write the windows drivers for your system, same with pretty much everything that's going on in the linux kernel, android, etc. Embedded wraps the entire computing space. Can't really say the same for any other discipline.
On top of all of this, there's a solid demand from the "mission critical" world for good devs. Airliners, satellites, rockets and cars all, by necessity, run extremely thin stacks consisting almost entirely of C (though some of us are starting the push for Rust). You can't just Python your way to glory in a fly-by-wire controller because that's how you get people killed.
Yes, the pay is mostly shit unless you work for a large company. Qualcomm and similar typically offers six figures starting. I work in aerospace but they're starting to get desperate as they no longer get to pay nothing for getting to build cool flying stuff. YMMV here.