> I could see a world in which we're all just writing tests in the form of something like Gherkin though.

That works great in practice, Gherkin even has a markdown dialect [1].

If you combine it with a tool like aico [2] you can have a really effective development workflow.

[1] https://github.com/cucumber/gherkin/blob/main/MARKDOWN_WITH_...

[2] https://github.com/jurriaan/aico