jQuery provided a DOM manipulation API that was the same in all browsers when there were lots of differences between browser implementations. While you could do everything using standard web APIs, that would be incredibly error prone and tedious at a time when `querySelector` was not a thing yet.

Lodash does way more than some basic functional wrappers. I've seen too many buggy re-implementations of debounce, throttle and groupBy at this point, it's not even funny.