Superstar goalies don't grow on trees, and if a team doesn't draft them they are pretty difficult to acquire via trade or free agency. Are there some potential concerns with Binnington? Sure, but I fail to see any realistic alternative that would satisfy the concerns you mentioned. We have a goalie who's good enough to win a Stanley Cup and I feel pretty good about that.
I'm not criticizing the organization or suggesting that we took a wrong turn this offseason. I think that spending $4M on Leddy was a better decision than tying up $10M on the goaltending. I don't think we had a better alternative this summer. That doesn't mean that we are a lock to get good enough goaltending.
If both of our goaltenders play like they played last season, we have a bottom 10 tandem in the league. I don't think that will happen, but it is far from a 'well you can never predict goalies so of course that is possible' scenario.
If one of our goaltenders bounces back to his level of play from 2020/21, then we will have noticeably worse goaltending than last year.
If both of our goaltenders bounce back to their level of play from 2020/21, then we will have slightly worse goaltending than last year (neither as good as Husso was last year, but both better than Binner was).
If we get the pre-COVID version of Binner, then the goaltending will be on par to last season. Better if we get rookie year Binner.
I feel pretty confident that Binner will bounce back to 2020/21 level play with an outside chance of being a touch more consistent. I have much less confidence in Greiss giving us 20-30 starts at roughly .910 goaltending.
I'm not predicting that our goaltending will be garbage, but it is absolutely the #1 potential reason we could miss the playoffs this year. Binner's 18-14-4 record was good for a 91 standings point pace last season. He wasn't good enough to get a top 5 offense into playoff position last year. We made the playoffs because of the safety net Husso provided (which ultimately led to Husso winning the #1 job in the 2nd half of the season). I'm not sold that Greiss offers the same safety net.
The Blues forced themselves to ride or die with Binner when they gave him top 10 starter money (which was a direct result of the inexplicable 2 year deal that walked him straight to his first summer of potential UFA eligibility). At that point, we committed to a strategy of cheap backups that hopefully wouldn't be required to be anything more than adequate. We needed (and fortunately got) more than that from Husso last year, which priced him out of our cap structure. We are once again going to ride or die with Binner and I don't view Greiss as capable of providing 30+ starts as a top 10 goalie if Binner falters.
There are worse situations to be in and I don't think there were any realistic backup options that would have put us in better shape. But there is absolutely reason to worry about the goaltending, because it is the only thing besides injuries that has a realistic shot of tanking this season.