I once thought that too. But after working under a jQuery ninja I learned that it's far more powerful than most people give it credit for. More importantly, it's significantly easier to reason about DOM changes in jQuery vs other frameworks because there's no magic at all.

For example, here is a SQLite playground that I built with a friend https://sql.glitch.me/. The entire frontend is only 100 lines of Javascript thanks to jQuery. I'd love to see what the React implementation looks like.