Most UI kits let you pass any style as a prop — radius, size, color, or a wall of Tailwind classes, whatever you need. That flexibility is exactly the problem: it turns every component call into a one-off styling decision, and no two buttons end up the same. Let's talk about practices that prevent building an inconsistent, unmaintainable code base that won't scale.
Did we just go full circle? CSS classes already exist.
For what it’s worth, modern component libraries compile the styles to CSS classes anyway. I don’t know why they choose to go through the convoluted process they do to generate those classes, but the user usually just sees classes at least.