Innate inertnessI want to get into styling the backdrop, but before that, I think it’s worth noting that the page behind an open dialog is inert . And when the modal dialog is open, the popover dialog is not in the top layer, making it inaccessible. It’s a really good question because the Dialog API and Popover API are super similar but designed for different use cases. Zell Liew has a concise answer:After a bit lots of research, I discovered that the Popover API and Dialog API are wildly different in terms of accessibility. So, if you’re trying to decide whether to use Popover API or Dialog’s API, I recommend you: Use Popover API for most popovers.