I actually used to do the same thing with the -, and by em dash becoming a thing I dived into the usage and history of it all, including ; and en dash. And now I'm using - less. But I don't use em dash more, just tend to throw a comma in.

Another weird one I learned. em dash spacing. The spacing AI tends to use is not preferred by publishers now, but is more AP style, perhaps picking it up from when it was more popular to have space between the letters. Europe tends to prefer spacing but with a en dash (and I kind of like how that looks too, but it doesn't fly if you publish in the US).