Nobody who uses Tailwind would suggest copying the same classes over and over again in the example you’re talking about. You would either still create a card component (Tailwind does have the concept of components), or if you were using a framework like Laravel you could create a card blade component that held the tailwind card classes in one place.
I wasn't talking about Tailwind, I was talking about vanilla HTML and CSS. I assumed the question asked of me ("what's wrong with"...) was asked in that context.