I don't really know much about this area of UI. Can you explain why this breaks accessibility? I did load it in reader mode (macOS Safari), and there were no paragraph breaks - is that similar to the experience of a screen reader?
If everything is a span, everything becomes just text.
It doesn't only apply to screen readers. Regular actions like keyboard navigation becomes broken. For example, on the page, you cannot tab between "click to expand" "buttons".
And so on and so on :)
> actions like keyboard navigation becomes broken
is also an accessibility issue. Not everyone can use a mouse. Keyboard navigation should be the easiest possible thing to test and ensure works…
…until features start getting killed because they can’t be made to work well on screen readers. I’ve seen it happen and it strikes me as unfortunate.