I don't see it as two ways in practice, just the legacy way for old projects (which still has good support), and the newer/better way.
Asking because my experience is that as soon as you have a large and complex component that needs to have multiple, mostly independent functionalities, you'll find the composition APIs to be a godsend. Not to mention all the IDE support. You won't see that until you have first have experience with it.
Also proper typescript support without annoying workarounds, that alone would make it worth it.
the `defineProps` macro is much, much better than the old way of declaring prop types, for one.