Indeed you don't need jQuery. Though, there are standards and there are market/industry standards. jQuery has become a market standard wrapper. If jQuery isn't used, developers will still write a wrapper to ease some of these methods. It is better if that is a common market standard like jQuery than everyone doing it.
The amazing part of jQuery still to this day, beyond the selectors (which can now be replaced yes), is the plugin system. Just like Python, there is a plugin for everything and if you don't like them or there isn't one, developers can easily make one and share it with the world and it just works (tm). It is the most easily pluggable javascript library. It creates a baseplane that developers can be more efficient in. Everybody tries to replace the jQuery selectors, animation etc but they miss that jQuery is a platform and a pluggable one at that. It is responsible for tons of productivity.
The amazing part of jQuery still to this day, beyond the selectors (which can now be replaced yes), is the plugin system. Just like Python, there is a plugin for everything and if you don't like them or there isn't one, developers can easily make one and share it with the world and it just works (tm). It is the most easily pluggable javascript library. It creates a baseplane that developers can be more efficient in. Everybody tries to replace the jQuery selectors, animation etc but they miss that jQuery is a platform and a pluggable one at that. It is responsible for tons of productivity.