Most languages make their blocks inside functions, classes, etc visible.

• end: Lua, Ruby (this was changed recently issue/PR)
• indent: Python
• {}: C++, Rust, ...

This added visible scope would make targeting the inside/body of a function much easier. Textobjekt queries that do this are currently very cumbersome to do.

The other advantage is tree-sitter based expanding/shrinking selection. Currently it is
expression -> whole function
with this change it would be
expression -> function body -> whole function
It would be much easier to select these code blocks without selecting the surrounding syntax.

I think just changing everything to block should be fine. The exception would be the top scope. Here we already have source_file, so an additional scope is not needed.