You're underestimating the appeal of sheer convenience. jQuery is convenient because it's terse, it's expressive and it has bloatloads of community support.

Most "standard" javascript APIs (especially the W3C DOM) are absolutely dreadful to work with, especially if you like modern javascript (a smalltalk-ish blend of "functional" and object-oriented javascript).

If IE falls under 5% of market share (not like it'll ever happen), jQuery will simply remove the now-irrelevant pieces of code. My proof for this is simple: http://zeptojs.com/

This is a 5k library aiming to implement the full jQuery API while restricting its compatibility to mobile webkit browsers.

As long as there is more than a single browser (and each Webkit port out there counts as a supplementary browser), jQuery will thrive.