Except Vegas has been to the Cup Finals and WCF in recent years, I'll take the guys proven to go deeper until Colorado actually gets out of the 2nd round. On paper doesn't mean anything, Vegas is weaker than a lot of teams on paper, they still smoke them when it comes to actual games.
Many ways to look at it.
You can also say Colorado outscored Vegas 16-8 in the 3 meetings they had last season and despite heavy injuries had the better record. They almost completed the comeback against Dallas where as Vegas fell flat in 5 games. They went deeper in the playoffs in 18-19 than Vegas and so both teams have 2 playoff round wins total from the last 2 seasons. None of the last 3 cup winners either had a SCF appearance or had not been there in 5+ years.
Yeah, Vegas made the cup finals in that magical year. Do i think the current Avs could do the same facing the same teams then? Yeah. They're better than 17-18 Kings or Sharks, Jets showed fatigue after a taxing NSH series and 1 day off. I think it's a narrow view to look at SCF appearances, reality is Vegas does not have the experience of going all the way. From that point of view these two teams are not as much apart in terms of experience as you think. For example the Avs gained invaluable experience coming back from 3-1. Vegas has never done that in the playoffs in their existence. They've beaten a top seed team in Calgary in 5. They've made quick work of a lower seeded team in Arizona. They've been in many different scenarios in recent years and came out on top. In turn, Vegas have done some things Colorado haven't.
You know what the Caps did the year before winning it all? They came back on the Pens from 3-1 down and then lost game 7.
All this is just speculation really and none of it may or may not matter. What we can do is to look at the teams objectively and what they're capable of right now. I don't see any reason to think Vegas is the better hockey team but each to their own.