I take offense to the idea of the "golden age fallacy".
Let's constrain fallacies to actual logical mistakes.
Some things actually have had a golden age -- e.g. for bebop it can be fairly accurately be told to be certain decades, and it's not wrong to point to that to say that things are not the same anymore.
(And even if individual outliers might produce an X equivalent to a "golden era of X" artifact, statistically it would still be true to say that now it's not like the golden era of X, if less such works are produced in total and even less consumed and appreciated -- e.g. if I make a great "Miami Bass" tune, it wont mean that the late eights weren't the "golden age" of Miami Bass).
In fact the golden age is so much not a fallacy, that is a valid historical construct (e.g. for Roman democracy the golden age was so and so centuries -- no ifs and buts about it).