Be out of fashion & be out of style

You have already had an answer to that. Didn't you like it?

https://able2know.org/topic/411890-1#post-6499871

In real-world use they have such different meanings that I would not recommend thinking of them as being interchangeable.

Style has to do with one's own sense of appearance and carriage. If you know your own style, you can't ever be out of style. Style is internal. It is about self-awareness.

Fashion is time-limited. Fashion is external and is about efforts to be like/look like others.

I appreciate people who have a sense of style, who know their own style.

I am not interested in people who try to keep up with fashion - whether that has to do with clothing/housing/cars or anything else.

Surely you can say equally well that "bobby sox and bangs went out of style years ago" or "bobby sox and bangs went out of fashion years ago", and mean the same thing?

I wouldn't. Bobby sox and bangs were a fashion fad. I don't believe they would ever be considered as stylish or being a style.

That usage is a bugbear in design/art crowds. Makes me shudder. Even reading/hearing ín style is a bit gag-inducing.

I am a complete amateur in these things. Was "rockabilly" a fashion or a style? I have to say that I am not a fan.

They're both mean the same thing, contextually speaking.

In regard to individual style, one would say something along the lines of "having no style." I've never heard "be out of style" to refer to individual sense of style.