I guess the distinction would be that in the formaction/formmethod case you'll also submit all the other form data, while the button action will just be an empt

I guess the distinction would be that in the formaction/formmethod case you'll also submit all the other form data, while the button action will just be an empty body. An extra blank form on the page and the form attribute on the button can work around that, and at that point the argument would basically be: this is super clunky.