the quest for the best--within limits

One of the easiest ways of narrowing down equipment choice is to use the Virtual Systems.
For example if you have tonearm x, and want to know which cartridge would be best, then search on virtual systems to find out what other owners of tonearm x are using. Check the rest of their system to find out if they have similar taste to you.
Make a shortlist and check reviews on the web.
I think this methodology will give you a better, clearer picture and more likely to make the best choice than hundreds of recommendations without any explanation.

The answers would be futile at best. Even if one searched
the archives or asked another "which is best"
question, the answers are as varied as the number of
different systems.

I think people re-ask old questions because it is easier to get personal value out of answers if it is part of a dialogue. I can re-ask an old question, get the same old answers, but then respond with follow-up questions specific to my situation. It's also possible that re-asking a question is helpful in order to get a more recent perspective... maybe technology, gear, research, or other elements have changed.

Some are looking for confirmation (validation) for a component they've already identified as a potential purchase.

when a discipline is subjectively based, e.g., art, music, literature and cuisine.

there are many algorithms that are implicitly used to evaluate what is experienced.

thus, having different standards for judging, makes it impossible to determine what is best.

further , sense perception is unreliable and varies from listener to listener, making the concept of what is best a useless exercise.

what is usually substituted for best is sentiment what someone likes most is usually what a person connotes by the term "best".