A notion, for your consideration:
We hold many a long-dead composer in extremely high regard. I neednt name any, thats sort part of the point/question.
But, consider times they lived in. Good quality instruments a were scarce, a carreer in music required the patronage of some monarch or similar, material to learn from was hard to come by (no interwebs, no printing press for a lot of them), lots of passing of the torch, apprenticing, fortunate circumstances and the like. Also, general standards of education were very much lower, as were comfort levels and standards of living facilitating you having free time and means to indulge in music full time, and aside from anything else, the planets population was much lower. But we venerate these people (again, just choose your favourites).
Obviously time (as in the test of; that they, whomever you picked, are still remembered and enjoyed, and have therefore been by all intervening generations to at least some extent) plays a factor in this, and likely the fashion in which those that were lucky enough to find a life in music would have gone about it with a devotion, in shear number of hours per day, that would put most of us to shame.
But, we have far more readily available instruments, of good quality for a low proportion of our income, we have everything humanity has ever known about music and how to play any given instrument at our fingertips, all making it easier, in principle for any given person to develop their skills/art/whatever, and to boot there are far more poeple alive today, so any quasi-rational way I can cut it there must be people that are as, how shall we say without getting toooo subjective about it....musically sophisticated? That'll do; more people as musically sophisticated alive today than at any other time in history. I submit to you that there are more (imma start naming names now for dramatic impact and shite) mozarts, beethovens, paganinis and so on alive now than, well, when they were alive.
Or,
They were 'better' whatever the $% that is, because their lack of distraction and scholarly devotion allowed so much more focus, so a persons potential (whatever the $% that is) might be better realised, and their work is therefore truly godlike and unmatchable by modern fickle, facebook and youtube addicted people.
I think the former. They are out there, proper massive geniuses, that will probably be forgotten since, for similar reasons, they cant stand out as much, and have as great an impact in such a musically prolific popluation as ours, but I think there are rather a few out there now that can be fairly compared to the great composers. If you agree, name some! I'll start: Tommy Emmanual, al di meola.
If you dont agree, why?