I think this can go both ways. There are lint rules that encourage explicit return types for exported functions and public functions, because return types are the interface between modules. As your codebases grow, having clear relationship and contracts between modules becomes more important. This goes doubly for modules distributed as NPM packages - you want the compiler to tell you when changing the body of an exported function constitutes a breaking change to your module’s API - and the easiest way to make that mistake is to change an inferred return type, and conversely the lowest-hanging fruit to prevent that error is to lint for explicit return types.