Additionally, I very rarely see roles in that area listed that someone from another fields could “break into”. Often they’re looking for someone who has significant domain experience, and by domain experience I don’t just mean my embedded software in general, but experience around the actual product target business itself (medical devices, cellular networks, whatever).

For example I looked at a job near working working on integrating 5G chipsets into boards. The work was relatively high level (you weren’t designing the 5G stack or anything, maybe at most writing some modem drivers) but they were looking for people who from that domain and had experience with all sorts of strange proprietary Qualcomm crap.