[goto11]

Yes but what is the the cost of accessibility? How much more expensive is it to use a <button> compared to a <div> with attached event handlers?

[lmm]

The cost of doing accessibility is the cost of doing accessibility testing. If you're not actually testing your accessibility work, using a button instead of a div is pissing in the wind.

[goto11]

Surely a button is more accessible than a div regardless?

[lmm]

Maybe, maybe not. ("Surely" using the browser's CSS animations would be more efficient than reimplementing them yourself in JavaScript - but if actually you benchmark it, the opposite is true). If you're not actually testing it, how could you possibly know?

[slver]

If only it were so simple.