There are more knobs to turn when you have an actual library, and you become a lot less fungible than a random collection of TW classes.

HeroUI faces the same problem, and now their React Native library includes an optional (paid) conpiler solution that makes it faster.

MUI has the same problem but besides templates they have their MUI X data components which aren't limited in complexity to what can be ergonomically copy and pasted to a clipboard.