There are downsides to this request, at this point in time (November 2024). The main downside is poor MDX support in VSCode.

First, we must recognize that VSCode is an incredibly popular IDE for many authors working in Docusaurus repos.

Second, we must recognize that many authors rely on VSCode's IntelliSense autocomplete features. Of particular importance in this case is that IntelliSense support for Markdown files (.md) includes something called "link path completions". Which basically means that if you want to link to another header in the same .md file, you start by typing #, and IntelliSense shows you a handy list of all internal headers to choose from. And if you start by typing ##, IntelliSense shows you a list of ALL headers from ALL .md files in the repo, which you can rapidly typeahead filter to the specific file you want as your link target.

So, here's the problem, at this point in time:

A. MDX files are supported in VSCode only by installing the third party MDX extension.

B. IntelliSense link path completions do not work in MDX files, because the MDX team has not built support for that in their extension.

What this means is that any Docusaurus author who uses VSCode suddenly loses a critical authoring shortcut -- a massive time saver -- if your suggestion is implemented right now.

Ultimately, I think we need the MDX team to improve their extension for VSCode to fully support IntelliSense "link path completion" before considering the change you're suggesting.