Okay, I'm not sure if Berube really was a good coach (Mike Yeo is a complete joke though) but the team did get better in 2018-2019 when he took over. Binnington replacing Jake Allen as the starter that year really helped. But like Binnington that year, maybe Berube just really caught fire at the right time. Binnington never replicated that season again.
I find his firing kind of weird, unless it was done to blow things up. This Blues team is NOT good. I don't think they're getting much more out of that team from a better head coach. They're old, slow, too many bad contracts. Overpaid a lot of guys for that cup. Binnington is one of quite a few of them. They're almost like Washington West (or maybe that's Nashville? Or maybe they're both Washington West?) only they haven't won (FLUKED) as many games or fluked their way to as many wins, though they did win a decent amount to start the year when Binnington was hot. They were overachieving for a while there. Maybe just Central Division reasons though.
Flyers fans hated Berube when he was a head coach there, and no one could really imagine him being the head coach of a Stanley Cup winner just a few years later after his tenure ended there. And also coming in and the team going from last place in January (or whenever it was) to cup winner that same June.