Sure but WAR takes that into account. Here are Markstrom's GSAX for every season he has had the majority of the games for his team:
2023: 0.385
2022: -0.150
2021: 0.207
2020: -0.144
2019: 0.054
2018: -0.023
2017: -0.032

So like WAR, two good seasons, two bad seasons and 3 years of mediocrity.

Yeah I agree with you on that, I think his price is extremely inflated tbh. I think hes really worth a 2nd rounder and a B prospect but Cap Friendly prices have gotten wild

His recent numbers (2 of last 3 years) are much better than anything before it. He looks to me like Ulmark from Boston. Middling for most of his career but better recently. The question is, do the better numbers correlate to a breakout or being on a better team?

Oh absolutely but The problem there is that there is no runway left, most good goalies in the NHL retire at like 38? He's 34 already and any late development is cancelled out by his impending regression. What a lot of people on here don't get is that value is over the longterm, people don't pay insane prices for 1 playoff run. You need to be pretty sure you're going to get at the very least 3 years of quality goaltending but preferably like 8 years if you are going to give up a highly ranked prospect who is still on his ELC. A first rounder isn't so much a problem and I'd be perfectly happy to send it out for an old goalie given the timeline of this team but anybody who thinks a 1st and Holtz is worth probably 1 post-season run with him at this level is wildly overvaluing him at least in my book