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.