React is an electric screwdriver. Real hassle: battery needs charging, need to insert correct bit, may need extendy bit for some jobs. But got an IKEA cupboard and not a simple shelf? Gimme that electric screwdriver!

In vanilla JS even small SPA projects can end up tangled or you are hand compiling what React would do for you for free.

Nit: in React events are events useEffect reacts to abstract state changes.