React isn't as thin as Preact (or whatever other small library there is), but that means that React has more functionality. This is absolutely true but 99% of

React isn't as thin as Preact (or whatever other small library there is), but that means that React has more functionality. This is absolutely true but 99% of React sites don't need the extra functionality if they've already accepted stopping supporting old browsers. Everyone who uses React should be testing Preact to see if their app works. It could well be a very low effort way to knock a few tens of KB off your bundle size.