That is neither proven nor disproven, for any edition (except maybe 4e

). It is as presumptuous to make the claim as to deny it - unless you have some empirical data to support one view or the other it's ALWAYS just been a matter of personal preference as opposed to ANY edition being manifestly superior. However, I do believe that ignorance of the history of the game and its development - including HOW it was played at various points in the past (as suggested by different sets of the rules) - leads to
questionable assertions and conclusions by many as to whether ANY approach to the game, older or more modern, is inherently better or worse. It is therefore not surprising to see Gygax - without whom the game would possibly not have come to exist at all (partly because he was the only one who set about actually formalizing the rules to sell them) - repeatedly cited as doing things QUITE differently, to support assertions WHY older approaches and older rules might still actually be
better.
Uh...no, it is
not presumptuous to say that Gygax's perspective is no more nor less "true" D&D than any other.
Older approaches cannot be better in the abstract. (Nor can newer approaches be better in the abstract!) They just can't. That's like saying that cars are better in the abstract than planes. They aren't, because they're
for different things. Likewise, older approaches and newer approaches to D&D-related stuff are
for different things. You would have to first assert that the playstyle and design-goals of early editions were
better than the playstyle and design-goals of later editions, which I'm absolutely confident you cannot do, not even in principle, let alone in practice.
In the absence of that, all we can do is set a conditional: "
if you are trying to pursue a Gygax-like style,
then..." But most people today aren't trying to pursue that, because (if we're being frank) Gygax-like playstyles are not particularly popular. They have their diehard fans and absolutely, positively
should not be neglected or spurned. But they also aren't for everyone, they aren't even for most people. These approaches deserve support, and we can critique whether that support achieves its design goals or not, but we cannot say that these approaches are
better than other approaches.
But we can also determine that
newer approaches TO Gygax-like playstyles can, in fact, be better than Gygax's approach! That's doing the "if you're trying to do X, then Y is better" thing. Dungeon Crawl Classics, for example, introduced (IIRC? I think they were first) the concept of a "funnel" adventure to get started. One of the serious issues faced by consciously old-school play is that it can take weeks or
months to get a PC that survives more than 2-3 sessions. A lot of gamers today simply do not have that kind of time to invest. But they still want to play, and they still want to have an experience
like the experiences of yesteryear.
Enter the character funnel: Each player plays several rapidly-generated, highly simple PCs through a brutally hard adventure. Most players will lose at least one character during the funnel, probably more; but that's fine, you have three or four or five or whatever. This teaches new players that characters are disposable, that losses are expected, that combat is swift and brutal and something to be avoided, that the
only things that matter are things which explicitly occur within play itself, that "builds" and other considerations do not apply here, etc., etc. And it does so in a way that compresses weeks or months of play down into a 1-3 session burst of frenetic (and hopefully fun) adventure.
Character funnels aren't for me. They're a design I have zero interest in playing. But I recognize them for what they are: a
brilliant solution to a real and serious game-design conundrum, how to preserve as much of the classic game experience as possible while easing its most burdensome aspects that make it a tough sell for the gamers of 2012-and-beyond (that being when it first released.) Character funnels are objectively an improvement over the rigidly Gygax-like approach to play, because that's literally what they were designed to be.
Let us not become the complacent mathematician who insists that you cannot improve upon Euclid. The
Elements were an absolutely amazing achievement when they were set down, two and a half millennia ago. But modern mathematics
is better. It couldn't exist
without Euclid having done so much, so well, so durably--but absolutely none of that means Euclid's ways are better than ours today. Of course, that doesn't mean that we have nothing to learn from Euclid's approaches either--there's something to be said for the
concreteness of his work--but without things like divorcing the concept of number from the concept of concrete distance, we could never have achieved calculus, and consequently, never have reached the stars.