Right now built in buttons don’t have “edit styles” option.
Use case scenario:
When a user tries to edit different buttons he doesn’t know the exact sizes of them so he can’t replicate all dialog boxes to look similar.
Yes, you can copy paste the same button on every dialog box, but that is inefficient when the user has multiple prebuilt button with already complex custom lists. So replicating them all would take a long time, opposed to just knowing the size of the button by pressing “edit styles” you can make all buttons the same size where applicable.