I think that could be true for for averages, but I usually don’t drink randomly selected wines. I pick wines I am familiar with and like. I think that I can find more wines I like at 20

You should google sommelier tests - they can name regions in blind tests, not just quality.

Whether it’s actually “better” in any real sense is debatable. But wines are certainly distinguishable

Most of us aren't sommeliers though. In a blind test the best I could do would be to say "I like that one, don't like this other one etc". And I feel I know a reasonable bit about reds and have done plenty of tastings over the years. I usually go for the best bang for the buck, and at the moment there's a bunch of great South American wines priced at around GBP5.50-7.00 that are great daily drivers.

Is it quality they can't identify, or price? Is there even an objective measure of wine quality? Price at least is objective.

Quality is inherently subjective, but there are widely adopted rating systems