It works two ways though, which I think is important. Yes, type systems check the shape of your data which is nice.

However, when sufficiently experienced, the type system also guides the developer into good program design. Type systems for me are more a design tool than shape checker.

The checker/inferencer helps me learn about assumptions I make about data in specific parts of my code, which allows me to remodel my data types to better fit my intent. This works cyclic until things just seem to ‘fit’.

Personally at least, this allows me to write far more complicated applications than I would ever be able to do without types. And it’s just very hard for me to imagine this wouldn’t be the case for any other developer.