The dynasty was supposed to be extinct in the free-agent/salary-cap era.

The Patriots were never supposed to win six Super Bowl championships from 2001-18 and own the AFC East for 11 consecutive seasons.

And now we have the Chiefs, appearing in their fourth Super Bowl in five years, and eyeing their third Lombardi Trophy in four years Feb. 11 in Las Vegas against the 49ers.

The Patriots were hated, just as the Damn Yankees were hated all those championship years.

The Chiefs? No Spygate, no Deflategate, a loveable head coach and a likeable quarterback — a kinder, gentler Dynasty.

But as the defending Super Bowl champs, they recognize they wear the villain’s bull’s-eye on their backs, nevertheless.

“Everybody wants to beat the Chiefs,” rookie receiver Rashee Rice said. “We’re the ones you want to take down, we got a target on our back every day.”

The Patriots defiantly won three Super Bowls after Spygate and won those three after Deflategate. These Chiefs were written off in late December after losing four of six games and have rebounded to be at their best when their best is required.

You start with the quarterback. Patrick Mahomes is to the Chiefs what Tom Brady was to the Patriots: a future first-ballot Hall of Fame quarterback.

You go next to the head coach. Andy Reid is to the Chiefs what Bill Belichick was to the Patriots. Belichick is a defensive savant. Reid is an offensive savant. Future Hall of Fame coaches.

It’s as good a place to build a dynasty as any. In fact, it’s the best place.

Brady and Belichick did it longer and better together than any head coach and quarterback, and that is why they are the GOATs.

Mahomes and Reid won’t have that kind of staying power because Reid will be 66 in March, and there is speculation that he could walk off into the sunset with a third ring. But Mahomes is just 28, and you better believe Chiefs GM Brett Veach would find a quality replacement to maximize the next decade of Mahomes’ career. Let’s not forget that Brady, at 43, won his seventh and last Super Bowl with Bruce Arians.

And therein lies the genius of Brady and Mahomes: They lift everyone around them on the field and in the building. They change the culture from hoping to win to expecting to win.

Another coincidence: Brady had Rob Gronkowski. Mahomes has Travis Kelce. Future Hall of Fame tight ends.

And because it always starts at the top, the Patriots have Robert Kraft and the Chiefs have Clark Hunt.

Reid, much like Belichick during the Dynasty years, was supported by quality assistants. From offensive coordinator Charlie Weis to Josh McDaniels, from defensive coordinators Romeo Crennel to Eric Mangini to Dean Pees to Matt Patricia, Belichick found trusted partners.

Reid and OCs Doug Pederson and Eric Bienemy were in lockstep, and DC Bob Sutton was followed by Steve Spagnuolo. Bienemy left this season for the Commanders, the Chiefs replaced him with Matt Nagy.

Belichick and Brady didn’t win a Super Bowl when Randy Moss was Brady’s go-to guy, but they won three after Moss was gone. Reid and Mahomes are gunning for a repeat even after Tyreek Hill was traded to the Dolphins before the 2022 season.

“They lost one of the best receivers in the National Football League,” former Giants GM Ernie Accorsi told The Post, “and they’re still winning, and they’re back in the Super Bowl.”

Belichick was not averse to taking a chance on players with baggage — Moss, Corey Dillon, Aaron Hernandez, Antonio Brown. Reid was willing to roll the dice on Kelce, Hill, Marcus Peters, Frank Clark, Kadarius Toney.

Belichick was able to find bargains in the draft basement (Brady, sixth round; Julian Edelman, seventh round) and in free agency, with Brady taking less than market value year after year after year.

Reid and GM Brett Veach traded up for Mahomes in the 2017 draft and have landed other gems in the draft (including seventh-rounder Isiah Pacheco) and free agency, but now will have to replace cap guru Brandt Tilis — who was responsible for structuring Mahomes’ 10-year, $450 million contract extension in 2020 and is taking his talents to Carolina.

Referring to the Patriots and Chiefs, Accorsi said, “They’ve picked the right players, and they replaced the players they’ve lost, but the constant is the head coach and the quarterback.”

Darth Vaderchick and Uncle Andy have different leadership styles — “Do your job” versus “I’ll take a cheeseburger” — but both are uncompromising in the pursuit of winning. Both have been adept at creating a culture and environment conducive to winning. Their relentless attention to detail knows no bounds. Both have a vision and a role for every player on the roster.

And both, of course, have had the luxury of an elite franchise quarterback who carries their message to meetings, practice and game days.

In a league where so many games are decided by one score, Belichick trotted out placekickers Adam Vinatieri and Stephen Gostkowski. Reid has trusted Harrison Butker since 2017.

The Patriots were the team we loved to hate. It’s difficult to hate these Chiefs, mostly because of Reid and Mahomes. But it’s every bit as difficult to beat them, too.