Then say one component on one page now needs to be styled differently.
You have 3 options: 1. Create a whole new class which duplicates much of the previous class 2. Create a smaller class which is intended to override some rules from the first class 3. Factor out the common styles into smaller classes.
All have some maintainability concerns, but taking the 3rd option to the extreme makes the problem non existent in the first place.
That’s the real strength of tailwind. Preventing a critical mass of one off styles from making your whole css setup unmanageable