Beyond just being wisdom for life as noted above, these things are incredibly relevant for one of the claimed design goals of 5e, and why it was always a flawed approach, because of another design goal.
Goal the first: "Make magic feel magical again." Goal the second: "Everything you loved about D&D."
Magic felt magical whenever any given person began learning D&D, because when you know nothing at all about a complex system, "magic"--in the colloquial sense of the term--is precisely what it looks like. If you showed a 13th century peasant a smartphone, they would likely have no way to characterize it other than "magic". If we (somehow) instantiated the ability to use and manfuacture smart phones in the 13th century, it would eventually become common knowledge (...if it weren't abjured for being devil-worship or the like), but for quite a long time it would be a supernatural tablet that glows with life and speaks with an impossible voice etc., etc.
When each of us was first learning D&D, that's exactly what we encountered. It was a system--we knew that, it's literally called a "system" on the front cover in most cases--but the "system" is a mystery to us, veiled behind the pages of a grimoire, so to speak. We become initiated into those mysteries by learning to play....but that very thing is what rips away the illusion of mystery. Once we have learned what the system is, what the system does, we can see it for exactly what it is: a systematic structure attempting to codify specific effects in specific ways.
But what this means is, you cannot possibly fulfill both goals. You cannot capture that experience of fantabulous wonderment if everything is required to work in familiar ways. Exactly as Umbran said, "Trying to recapture an RPG experience from your youth is like trying to recapture your first solo ride on a bicycle, or your first kiss. It cannot be done." But that's precisely what made magic magical when we were first learning the game. Everything was possible because ignorance shielded us from the harsh truth that it was always only one specific thing, and a pretty rote thing in most cases.
I railed against this all throughout the "D&D Next" playtest, and was roundly ignored, because the paradoxical promise of mystery-in-familiarity was a siren song to the folks to whom 5e was specifically targeted. It, like "modularity", promised everything folks ever wanted. Now, today, folks have (at least begun to) come to terms with the disappointing truth: those promises could never have been fulfilled.
Which is part of why focusing your design, not on airy-fairy awesome-sounding buzzword phrases (like "Make magic feel magical again"), but on the specific experiences you want players to have, is so incredibly important in game design. Airy-fairy promises can help a game coast, potentially for years. But when the honeymoon finally wears off--as it always will--the criticism will begin, and it's not going to be satisfied with buzzwords anymore.