Upsets happen, injuries happen, and the "better" team doesn't always win. That's the Madness part of March Madness. Alabama, Houston, Purdue, Kansas, Arizona, UCLA, Texas, Marquette didn't beat who was in front of them. UConn, SDSU, FAU, and Miami did. Does that mean those were the best 4 teams last year? Probably not. But it's win-or-go-home every game, and those four won when it mattered while the others couldn't get it done.
There is a valid hypothetical question: "if UConn had to play Kansas, UCLA, Houston, Alabama, could they have won it all?". I don't know. Maybe, maybe not. Their advanced metrics and OOC dominance indicate they could, and they already blew out Bama early in the season. But it's all hypothetical.
There is an equally valid hypothetical question: "If Kansas couldn't beat Arkansas and UConn blew them out, if UCLA couldn't beat Gonzaga and UConn blew them out, if Houston couldn't beat Miami and UConn blew them out, if Alabama couldn't beat SDSU and UConn blew them out, could any of those teams beat UConn?". I don't know. Maybe, maybe not. All hypothetical
But what I do know is that UConn ran every single opponent off the court en route to 6 blowout wins and a National Championship. That's all that I really care about lol