There are certainly diminishing returns on many of the aspects coffee enthusiasts care about. But when I started experimenting with an Aeropress and some better

There are certainly diminishing returns on many of the aspects coffee enthusiasts care about. But when I started experimenting with an Aeropress and some better coffee I found it interesting that there were many fundamental aspects I could easily taste. Temperature and grind settings can get very obvious quickly. And also the difference between roast levels or some kinds of coffee beans/preparation are not difficult to taste. And I don't trust myself to distinguish any of the more subtle tastes coffee enthusiasts talk about. But once you e.g get into arguments on whether high-end grinders with conical or flat burrs are better you're far into the diminishing returns that might not survive a blind test.