I don't see how that follows. There's an enormous amount of different $20 bottles. There's probably enough different ones every year that if you try to you can have a different wine every single time you drink and still spend < $30 (to factor in shipping from further) per bottle - though going so hard on exploration without exploitation of the ones you find you like seems suboptimal anyway.
My experience is that the $20 bottles tend to be made to fit into <50 archetypes. The producers are trying to fit into a specific flavor profile, and are very good at hitting it. There are variations, but usually I would think of those variations as "imperfections," not as "character."
Once you get to $50 and above, they are trying to show you something unique, perhaps an expression or a particular flavor they like or an expression of the local terroir.
Sure, there are thousands of different $20 bottles, but they barely taste unique. It's like cheap coffee. Sure, there might be minute differences between the hundreds of cheap brands but they are barely discernible
That's definitely not true. I occasionally buy 5-6 random 8-20e wine bottles from the local supermarket and they typically vary massively. Even when I order my favourites trying others listed as similar all taste very different to me.
Maybe 50 years ago you couldn't get a cheap good wine without doing it one of five ways but modern logistics allow winemakers to make good wine cheaply with a wide variety of different products and twists.
