I never said 5e was perfect. But according to some, practically any version of the game would have had as much success. I disagree.Nobody's saying that, so I'm not sure where you got that idea.
Instead, what people are saying is, "You cannot reason from '5e is doing well' to 'therefore, 5e is very nearly perfect.'" Which someone here explicitly has done, and considered "98% perfect" a form of walking back, a compromise position.
Do you see the difference? I, and others, are saying that there's stuff in 5e that either didn't do anything positive or negative for it, or that (in some cases) may even have held it back. That's not a particularly damning analysis, and it certainly isn't "it's practically a minor miracle 5e is successful." Yet we're going up against people who, very explicitly, think 5e is literally actually perfect, or "98% perfect." I hope you can see which of these two positions is extreme and which is fairly moderate, albeit more critical than the average D&D fan at the moment.
The original versions of the game came closest, but RPGs were in their infancy. 3.5 was too complex for a lot of people, and so on.
Yes, cultural shifts helped. It also needed a game that was approachable with mass appeal.