Unobtrusive - Remove Event Handing From The Markup?

From my understanding the main feature of unobtrusive JavaScript is to remove event handing from the markup.The main reason for doing this is to avoid repetition of code.There are also other reasons but that is the main one. e.g. no having to write <tag onclick="function()" > over and over again. This traditional event handling method makes code less maintainable.However is it worth writing unobtrusive code when we consider the following:

1, Server sider scripting laguages can be used to avoid code repetition. e.g. we can use a loop to add multiple onclick event handlers to all the elements of a navigation list. Thus we would only have to write onclick="function()" once.

2, Unobtrusive coding makes the code harder to follow.It is easier to look at the markup to find out what happens when an event occurs on an element rather than having to look through wades of JS code to find the correct event listener. This is especially true when a team is working on a project. It is easier to find out what another person has done when the traditional model of event handling is used.

3, Unobtrusive coding means longer and more complicated code. Also there there is a need for having to deal with browser differences.I know this can be reduced using libraries such as JQuery. Is it worth using such a library?