The truth is that "Elite" is entirely relative. Does "Elite" mean competitive for an olympic medal? In that case, there are no Elite American marathoners and a handful of T&F athletes overall. So, it doesn't matter if one runs in the 16s in middle school off no training, as they really need to be born Kalenjin, right?
The OP seems to be using the term "elite" to refer to very competitive HS runners (if female) or (if male) a strong runner in a small league. The point is that you and the OP have very different definitions of elite. You're thinking about top-tier D1 NCAA runners (who, by the way, are probably similarly less than elite to those in Iten/Bekoji); the OP is thinking simply about a tier or two above current level.
So, to the OP - yes, you should definitely do it and you will almost certainly improve. How much you improve and how "elite" you become is eventually going to be determined by your genetics, but you probably won't find that "ceiling" for many years if you continue with steady and consistent training.
And, by the way, I had very similar times to you in HS - 20 min 5k which I brought down to 18 min after a first season of real training. I also wanted to get better and find my ceiling and - though I'm sure formerD1 wouldn't consider me elite - I've now been at the Olympic Marathon Trials, World Championships for USA, and have a shoe contract (9 years later).
Stick with it for the sake of getting the most out of yourself, not necessarily because you want to become "elite". As you've seen, everyone has a different definition and as you get better, your own definition will get harder and harder to meet anyway.
Good luck!