To be fair, when discussing the lack of content and longevity in the game new players are somewhat irrelevant because their experiences will be biased in a different way, i.e., the game will feel as though it's exploding with content due to them having only just started playing. That's generally why veteran players, be they content creators or a forum/reddit poster will focus on current content releases. A major criticism of FFXIV spanning multiple expansions now has always been content longevity. If you're a veteran player, you typically will run out of things to do long before anything new releases no matter how many breaks you take. Of course, this does depend on individual player time and investment but unless you're playing 2-4 hours a week, there simply isn't enough to last.
It isn't that we forgot what it's like to be a new player but rather it isn't relevant to the discussion.