The first third of the sixth and final season of “Cobra Kai” started streaming on Netflix July 18, and the seams are showing in this latest iteration of the 40-year-old “Karate Kid” franchise.

Considering that this all started with a rousing but unambitious young-adult riff on “Rocky” in 1984, it’s amazing that “The Karate Kid” sustained five feature films, and an animated series, even before “Cobra Kai” launched, originally on YouTube, in 2018.

While “Cobra Kai” has hardly been flawless, it’s a gravity-defying show for the mythos and character development it’s yielded, all from a relatively basic premise of teens and tweens turning to martial arts to resolve their social differences.

And yes, “Cobra Kai” depicts a “heightened reality” in which kids and adults alike relate to each other at an adolescent emotional volume, allowing their heated tempers to propel them into physical fights far more quickly (and fortunately for them, with far fewer enduring consequences) than would be the case in the real world.

But over the course of the series, we’ve seen this gradually expanding cast evolve and mature. That’s true even of the internecine feuds I found irritating in this show’s earlier seasons, which they were fueled more by stupid miscommunications than by substantive ideological divisions. Those now serve in retrospect to highlight how far everyone has come in their personal development.

Indeed, the irony of the first third of “Cobra Kai” Season 6 is that the buildup to its cliffhanger ending feels like a bit of a step back precisely because it begins by establishing how much our players have gotten past so much of the petty strife that had defined their dealings previously.

Not only do former rivals Miguel Diaz (Xolo Maridueña) and Robby Keene (Tanner Buchanan) seem to have put their former grudges behind them to form a fast friendship, but we also see once-bitter enemies Samantha LaRusso (Mary Mouser) and Tory Nichols (Peyton List) own up to their respective mistakes. The grief they caused each other brought a fair amount of drama to the series.

Even the hotheaded Johnny Lawrence (William Zabra) takes the lessons of Daniel LaRusso (Ralph Macchio) and Chozen Toguchi (Yuji Okumoto) to heart, not just to expand his repertoire as a martial artist, but also to grow into his newfound role as a provider for a blended family.

Having known a number of martial arts practitioners, one lesson they all imparted to me — which “Cobra Kai” Season 6 finally grapples with in earnest — is the idea that, when properly practiced, martial arts should not only teach you how to defend yourself in hand-to-hand combat, but impart a sense of balance throughout your personal life.

Chozen’s advice to Johnny hammers home that a philosophy such as the fictional “Miyagi-Do” should lead one to become a better person.

All of which makes it so frustrating when a number of these characters lapse back into dumb bad habits for the sake of creating dramatic tension on the eve of Daniel and Johnny’s students competing in the international Sekai Taikai tournament.

By contrast, easily the most compelling plot thread of this season is seeing former Cobra Kai sensei, and current fugitive from the law, John Kreese (Martin Kove) return to where he himself was taught martial arts, by Master Kim Sun-Yung (C.S. Lee) in South Korea.

Even after all these years, Kreese remains a fascinating animal, a manipulative and pitiless beast who’s sworn to renounce whatever lingering shreds of humanity he has left, and his sinister outlook continues to seduce students with too much pent-up pressure and not enough release valves for those feelings.

For all his ruthless brutality, Kreese reveals a softer, almost paternal side toward Master Kim’s granddaughter, Da-Eun (Alicia Hannah-Kim), who’s granted enough depth to at least slightly offset her problematically stereotypical dragon-lady persona.

I’m giving an incomplete grade to the final-season revelation that Mr. Miyagi had a shadier past than he’d shared with Daniel, because until I find out what that mystery is building toward, it feels awfully last-minute to wait until now to spring such a surprise on us.

My jury is likewise out on whether it was worth introducing former Cobra Kai pupil Stingray’s latest scheme, even though Paul Walter Hauser is an absolute treasure of a performer, who can transform even the most needlessly mundane dross in a script into gold.

I have enjoyed “Cobra Kai” throughout its run, and I eagerly await the remaining two-thirds of its sixth and final season. That said, this latest batch of episodes has also convinced me that this show will have wrung every last drop of potential out of its premise by the time it concludes, so the “Karate Kid” franchise should be allowed to retire at last.

Of course, it won’t be, because yet another “Karate Kid” film is due to be released next year, but still.