Regarding Sorbet and Rails, I recommend Tapioca [1].
The Rails app that I worked on had a few edge cases Tapioca didn't cover so I wrote a simple script to load the Rails app and generate RBI files (e.g. generate RBI definitions for fixture methods in ApplicationTestCase). The Tapioca codebase helped provide a path for that [2]. Tapioca also continues to add to their DSL compilers. The work to integrate Sorbet paid off very quickly.
Also, T::Enum and T::Struct are handy in any Ruby codebase.
The Rails app that I worked on had a few edge cases Tapioca didn't cover so I wrote a simple script to load the Rails app and generate RBI files (e.g. generate RBI definitions for fixture methods in ApplicationTestCase). The Tapioca codebase helped provide a path for that [2]. Tapioca also continues to add to their DSL compilers. The work to integrate Sorbet paid off very quickly.
Also, T::Enum and T::Struct are handy in any Ruby codebase.
[1] https://github.com/Shopify/tapioca [2] https://github.com/Shopify/tapioca/tree/main/lib/tapioca/com...