Tools are great, but I'm not a fan of the idea of needing special tooling outside of the source code itself in order to be able to understand it.

Maybe it's just me, but I would hate to imagine living in a world where my projects might be incomprehensible if I ever lost my .vimrc

In this case it would be a pure value-add, because the fallback is the way everyone can evidently cope with anyway.

I'm not sure that's entirely true. If a large proportion of people use a more advanced development tool, it sort of becomes indispensable, because people design the software to be edited with the tool, such that it becomes difficult to edit it without the tool.

For example if, today, I checked in code like performRequest(request, response, null, null, null) you probably wouldn't consider that good code, as it's not clear what the nulls mean there. Most people today would try to not write code like that. But if everyone was using an editor which displayed the parameter names, then it'd be fine. People would write that code, check it in, and so on. Which would mean that those people without the tool would have to confront such code.

IntelliJ does this in Java. It only does it for those arguments where the meaning could be unclear. For example, true/false or null.

Rust-analyzer does this, and I find it much more helpful than I thought I would

What editor or IDE do you use rust-analyzer with?