Authentic means genuine. Genuine means real. Real means … actual? Existing? Don’t worry: There won’t be a philosophy test at the end of this post.
Words like “authentic” and “genuine” are supposed to make you feel like you’re getting the best possible version of something: authentic handicrafts, authentic mayonnaise, authentic salsa-dancing lessons, etc. More than that, you’re supposed to feel that other versions of the authentic thing are cheap imitations. They are tasteless, soulless, and hastily assembled.
And you, you’re smart enough to know the difference. You have great taste. You know how things are supposed to be.
Like most stories people tell you when they want you to buy things, this one is completely fictional.