I've seen a lot of push back on adding type checking to Python but we had a similar case at my company where we tried it out on a new project and the clarity and readability of the code was immediately beneficial to the entire team. Perhaps it's something well suited to larger codebases.

It's $current_year and there's still debate whether checking stuff at compilation time is better than at runtime?

That's not really the debate in Python :)

Almost every Python user now has to "deal" with type annotations. It's tempting to gradually add type annotations, it's nice documentation.

But it also rubs me the wrong way to have annotations that are never checked(!). In many codebases, you might just have "casual" style type annotations in Python, and nothing ever asserts that they hold. That's nagging on me, a bit.

Never checked? They're statically checked.

Also, tooling like https://pydantic-docs.helpmanual.io/ can do runtime checking for important parts of your app or you can use this https://github.com/agronholm/typeguard to enforce all types at runtime (although I haven't measured the performance impact, probably something to do in a separate environment than production?).