I'm not saying that it's literally impossible to recreate a commercial e-liquid, just like it's not impossible for a home cook to recreate a dish made by a cook in a 5-star restaurant. I'm just saying it very improbable to get it exactly the same and the proof is in the amount of good clone recipes that are listed on ELR. Just like the creators probably, I've been very disappointed in my months long hunt for a few good clones when I started with DIY. Again, I'm not saying they're bad recipes, I'm saying they fail in direct comparison to the original.
There are 1000's of different ingredients and no, not all those ingredients are accessible everywhere around the world. There are not only all these ingredients but also the unlimited amount of different combinations of ratios that these ingredients are used at and then you also have the techniques and equipment used to make the recipes.
I'm not saying that I know it all, I am saying that it's very NAIVE to think there is just one way of mixing a e-liquid. Flavors are chemicals and each individual chemical interacts in a certain way with another chemical. Nobody needs a PhD in chemistry to know this.
There are differences in the chemical process whether you throw everything in a bottle and let it sit to do its thing, or whether you're going to follow a certain order, apply heat or other mixing methods to individual components etc. I'm sure not every commercial company works with difficult mixing processes, some do, others don't. It's just because of the sheer amount of ways of making a liquid that I say it is nearly impossible to make an exact clone.
This is not just my opinion, there are plenty people in the industry who say the same thing. One thing is the ingredients.
Of course, this "argument" could be over if you redefine the definition of the word clone. To me, a clone is something that looks, smells, tastes, feels the same as the original. If you take it under a microscope it may be different, but the general experience must be indistinguishable from the original. If it's not, it's a bad clone or not worthy of being called a clone.
If your definition of a clone recipe is something simply within the same flavor profile, then sure, OK, you'll find dozens or hundreds of good clones around and I'll take back every word I said. Otherwise, I think the list of clones on this site, from the 70K or so public recipes can be counted on a hand, maybe 2... because sure, there are some really simple recipes out there that are "perfectly" cloned. The moment you start adding flavors and go from 2 to 3 to 4, it becomes exponentially improbable that you'll get a real true clone. Again, no chemistry degree needed, just 1st year highschool math.