EzekielRaiden
Follower of the Way
By this standard, 5e's honeymoon ended shortly after it was published.It's about cycle she not actual age.
Many "popular games" don't have in internal discussion on the flaws of the game and how to fix them. They are in honeymoon stage still. No subreddits or forums on fire with "X is broken" or "Y doesn't work" threads.
Personally, I consider the "honeymoon phase" to be the period where discussion is almost totally dominated by effusive praise. For 5e, that period lasted about six years. Because, let me tell you, as a critic of 5e? That period was almost unbearable. For a while we couldn't go two months without someone posting yet another "golly gee willikers, I just can't get over how amazeballs perfect 5e is, let's talk about it!" Toward the end of that 6-year period, it did taper off a bit, but then you had people basically reacting to that tapering off by being all "suddenly folks aren't showering 5e with every praise-word known to man and some unknown to us, let's fix that!", but that period was (thankfully) short-lived.
Once Tasha's came out, it became possible to criticize 5e at all, without getting dogpiled by the people insisting how utterly amazing every part of it was. Once the (as always, incredibly stupidly-named) "One D&D" playtest was revealed to the world, it actually became possible to engage people on that criticism. I distinctly remember, sometime around 2018-2019, having discussions on this very forum where folks INSISTED that the 5e DMG was one of the greatest DMGs ever written, and moreover that anyone who said otherwise had an "agenda" or something ridiculous like that. Like literally casting aspersions at the very thought of criticizing it.
Now? Oh, now we get folks using what I've heard called the "slow breakup" technique, where things near-instantly flipped from "there are no problems" to "ugggggh can we PLEASE stop talking about those problems that everyone has always recognized???" In other words, we skip from denying there is any problem at all, to rejecting further discussion because it's pointless, without passing through that crucial (but, for fans, unpleasant) middle step of ever actually talking about the problems.