Components have always had JSX markup along with data manipulation logic. CSS in JS and styling co-located with component extended this consolidation of cross-cutting concerns.
These, along with not manually updating DOM state as you mention, all fall under declarative aspects of React.. which concurrent rendering and Suspense are consistent with and essentially an extension of.
https://www.youtube.com/watch?v=x7cQ3mrcKaY
Components have always had JSX markup along with data manipulation logic. CSS in JS and styling co-located with component extended this consolidation of cross-cutting concerns.
These, along with not manually updating DOM state as you mention, all fall under declarative aspects of React.. which concurrent rendering and Suspense are consistent with and essentially an extension of.