Did you forget that rabbanim ended up deciding to close the shuls? Pick a narrative. Either they were mistaken for closing the shuls at all, or they're mistaken for doing it very late. Or is it that every single Rov closed at the exact perfect time, some weeks before others?
Every Rav that didn't say he was mistaken for not closing earlier, closed at the perfect time if that's what his daas Torah dictated as the right time.
There's allowed to be amchlokes.
The notion that there was 1 "right time" can only be true if you're going solely based on medical experts. Then it's black and white. Either it was spreading and dangerous or not.
But we go with daas torah, and every daas torah is allowed to have his opinion of when it is necessary or not.
They decided in early March the data didn't call for it, and as more data came out, some decided to close then. And some still didn't think it was warranted until a week later. And some thought it was never warranted.
Eilu Va'Eilu Divrei...