Last I recall: sorbet itself is quite good once it is well established in a project, but adding type checking to a project (especially a Rails project) is a lot of work.
I just completed a big refactoring. We have a good suite of tests. But Sorbet has provided an added layer of confidence. Especially when it comes to the treatment of null values. Sorbet will raise an error if you try to call a method on an object that may be null. So it forces you to think through: what should happen if the object is null?
So the tests combined with Sorbet typechecking made that we could just almost blindly deploy refactoring after refactoring, with only a handful of bugs for several 1000s of lines of code changed.
You can get pretty good value from things like intellisense in your editor, knowing that the constant you're referencing or method you're calling exists etc, but most libraries have no typings in sorbet-typed (beyond `T.untyped`).
The last post on Sorbet's blog was from 2022 https://sorbet.org/blog/, so I'm not sure how actively it's being developed. (compare that to typescript where you have a post every month https://devblogs.microsoft.com/typescript/)
In his most recent interviews the philosophy can be summarised as "if you love types, good for you, but rails isn't for you"
It also help with autocomplete and linting.