chondle
Say what you will about the relative inelegance of jQuery, at the time of its release it certainly made JS--particularly DOM manipulation and AJAX--very accessible and cross-browser compliant. It definitely made articles like this seem quaint. [1][2]
At about the time of jQuery's release, Flash development was a viable alternative for smaller sites. I was doing bits and pieces of freelance around 2007 and after the iPhone came out, even my least tech-saavy clients stopped talking about Flash.
Pretty sure that these two bits made it so that every front end dev/ designer in the world was at least passably decent at Javascript by the time Node arrived.
[1] http://boxesandarrows.com/htmls-time-is-over-lets-move-on/ [2] Also, Mootools and Prototype and YUI etc, but jQuery is the one that became ubiquitous