“Better” is subjective. Boston’s defense is inarguably better than the Blues’, and Swayman hasn’t exactly been a playoff horse to this point.
Swayman had a .933 in 12 games in the playoffs last year. He was dominant against the Leafs and very good against the Panthers (especially in the back half of the series when their backs were against the wall). His career .922 SV% in the playoffs through 18 starts is noticeably better than Binner's .910.
Binner had the second-best goals saved above expected last year, and seems to be capable of getting locked in and tuning out the noise or moving past a bad prior game.
Moneypuck has Binner at 5th in all situations. Swayman was 4th despite GSAx being a cumulative stat and him playing fewer games. Swayman was also 4th if you looked at GSAx per 60 while Binner was 9th. Swayman was also ahead of Binner if you just look at GSAx at 5 on 5 as well.
Binner followed up a 4+ goal against game with another 4+ goal against game 8 times last year. It happened to Swayman twice. Boston was for sure better defensively, but there is every indication that Swayman has the same ability.
Swayman is younger, yes. But so what? It’s not like Binner and Hofer are at risk of aging out in the next five years.
Binner will be 33 at the end of his contract in 3 years and 35 in 5 years. If he is still performing as a legit #1 guy at the end of his contract, we will either need to let him walk or pay him more than $8M a year on a contract with uncomfortable term. Age is absolutely a factor.
Those two combined make less than Swayman would command and who’s to say Swayman doesn’t wilt behind the Blues leaky team-defense.
We're just a year removed from Binner putting up brutal numbers behind the crappy defense. Who's to say that we can count on Binner to be the 2023/24 version every year for several more years? Binner wasn't as bad as his numbers looked in 2021/22, but he certainly wasn't great. Swayman has been very good at every stop of the way in his career and Boston's defense last year wasn't nearly as good as it has been in year's past.
I genuinely don't see an argument for Binner over Swayman on a strict 1 to 1 comparison and I say that as someone that very strongly believes that Binner should have gotten Vezina consideration last year.