Revamped testbed

Complex image alternative (complex-images)

Complex images have an aria-describedby attribute linking to a more detailed description elsewhere on the page.

Non-descriptive figcaption:

This complex image element has a non-descriptive <figcaption>:

Business plan categories — This is figcaption description.

Note: Hard to implement, because you need human / AI to check if the figcaption is descriptive.