Yeah I also get this feeling that a lot of junior devs decide they don't really want to do it anymore. It's hard to get numbers on it because they will still have a related job title.
Of course, once the Great Recession hit, myself and many others that I graduated with either left the profession for other employment or simply never found jobs to begin with (that was me). Luckily I was already programming in grad school, and what was something I was filling my time with while looking for an architecture job became a new profession and I never looked back. Given all the comparative benefits of Software Engineering over Architecture, it's been a good move for me.
I've actually ended up in a tech job that hits those a bit, so I am doing a bit better these days at least.