I think the truth lies somewhere in the middle. A lot of panicky GMs handed over some insanely good pieces (Minnesota essentially handed over Tuch and Haula because they were terrified Vegas was going to take Dumba, for example) and of course there was the insanity that Dale Tallon pulled when he literally gifted 2/3rds of a top-notch scoring line to Vegas because he was pissed off at Panthers ownership and the guys who temporarily replaced him. They also got lucky--in no way, shape, or form was anyone prepared for William Karlsson to go from career 4th liner to star center. He's come back to earth a bit since then but that remains a very good two-way player. The Theodore move was also the result of an incompetent GM who is no longer in the NHL.
So there were some savvy moves, there were some gifts thanks to dumb GMs and a new situation that the league was apparently not ready for (they were the second time though), and some dumb luck. It's a shame Vegas, as is the city's nature, got greedy and quickly whittled away the depth they procured so magnificently in that first magical year. There's seriously hardly anyone left apart from the Wild Bill Line, Carrier, and McNabb. And they're likely getting rid of Reilly Smith this summer.
To be fair to Ronnie Franchise, the big names available (Duchene, Johanssen, Tarasenko) all had tons of money and term, and were all coming off career-low seasons, or close to it. There's a reason the GMs of those respective teams had those guys available. No one could have easily predicted that all three would have bounceback seasons. I'd also argue that with Duchene and Johanssen, those two are bound to regress at least a little next season. Scoring has been absolutely insane this year and Duchene especially is riding a ridiculous streak where he just can't miss. It's easy to look back and say they should've taken one or two of those guys but at the time?
Where Francis faceplanted IMO was in three areas: Goaltending, defense, and coaching. For some reason, Francis is very conservative, but when he takes a big risk it almost always blows up in his face. Victor Rask is a prime example, so is Scott Darling. And for some inexplicable reason he bet big on Grubauer, when his own analytics team should've been telling him his Vezina-finalist season was an outlier. He also went out of his way to build the slowest, least skilled blueline in the entire league. Lastly, he made a truly uninspired hire in Dave Hakstol, who is definitely the guy you want if the idea is to play it safe. If you're trying to excite a new fanbase, this was absolutely NOT the way to do it. It sounds like fan attendance and ticket sales reflected this as well.
I suppose you could argue that Franchise should've taken a chance and gotten a big-ticket player, but IMO where he went wrong was not procuring more speed, which should have been very easy. It's what the Minnesota Wylde did when they started out (and with draft rules far less favorable than what Seattle had), they got a lot of low-skill scrubs, but made absolutely certain they could move fast, especially up front. And this was while the league was still in the throes of the Dead Puck Era. They could've been excused if they had done what Seattle did roughly 20 years later. They didn't. And for Seattle to get as big and slow on the back end as they did in 2022 is just...confusing as hell to me.