It has everything to do with your point, which was that average goaltending is more than enough and investing in a known commodity like Markstrom is foolish for a team that is otherwise on the cusp of a legitimate cup window yet has no other plausible internal options
1. Of course average goaltending could be enough. Colorado got average goaltending during their Stanley Cup run where they steamrolled through the playoffs and went 16-4. You also have situations like with Vegas last year and St Louis in 2019 where you get goalies who have a hot stretch/year out of nowhere (Hill in 2023, Binnington in 2019).
I don't have a problem with investing in known commodities at goalie (I'm very in favor of making a big offer for Saros and looking to extend him), my problem is investing in a 35 year old goalie that just last season had a below average year in Markstrom.
Also just because there's no plausible internal options doesn't mean there's no other external options. LA got a good goalie tandem for less than $2M in one offseason with Rittich and Talbot. The Maple Leafs found a good goalie in Joseph Woll, Red Wings signed Alex Lyon, Joey Daccord came out of nowhere to have a great year for Seattle. There's clearly other options apart from Markstrom.
Vegas is cherry picking, the exception that proves the rule.
By your logic it’s stupid to pick a QB high - the Pats got Brady in the seventh, right?
Of course unexpectedly catching lightning in a bottle is a good thing.
Expecting to do so is no way to manage anything.
Comparing QBs to Goalies is downright insane. Go look at where the top QBs were drafted and go look where the top Goalies were drafted. The variance in goaltending performance from year to year changes wildly, especially once you get out of the top 10. Where as the top QBs from year to year in terms of performance are largely static.
You also use these terms lightning in a bottle or exception to the rule as if there's not a large number of teams from year to year that somehow catch lightning in a bottle. Daccord in Seattle, Lyon in Detroit, Talbot/Rittich in LA, Ingram in Arizona, Woll in Toronto, UPL in Buffalo, all goalies that were either acquired cheap or had little expectation going into this season that have performed above average or better this season. You also had Georgiev, Hill, Gustavson, Andersson/Raanta all acquired for cheap recently who went on to have big seasons on playoff teams.
I guess Vegas, Colorado, Carolina, LA and Toronto haven't gotten to their contention window yet.