I too am a retired teacher. I got my certificate in California back when getting a certificate meant one had to graduate college with a ‘real’ degree and then spend a year post-grad to get a teaching certificate.
History, which is what I taught for many years, is not considered important enough to require that a teacher actually know anything about history and in larger schools is given to a sports ball coach to fill out his day.
If one gets qualified to do special ed, that is what you’ll be stuck with. I’ve known some teachers who tried to somehow get their special ed qualification removed from their record.
I'm a substitute teacher at the high school level in Southern California. Most of the history classes that I have subbed for have been taught by coaches.