How do React Suspense and concurrent features like useTransition change how you architect data-fetching and UI responsiveness?

Imagine you're building with LEGOs. Normally, you have to wait for each piece to be handed to you before you can start building. Suspense lets you start building with the pieces you have, and when a new piece arrives, you can add it without starting over. useTransition is like saying 'I'll wait a tiny bit before asking for a new piece, so I don't drop what I'm already holding.'