You still need to write the initial block of code. Advocating for non-custom elements just because it already exists in Bootstrap or Foundation is an easy way o

You still need to write the initial block of code. Advocating for non-custom elements just because it already exists in Bootstrap or Foundation is an easy way out, especially for UI uses. It doesn't matter how an element was created as long as it's re-useable - there's nothing stopping you from handcrafting your own UI elements and re-using that block in your design system...