The README for Cash is straightforward:
Cash is an absurdly small jQuery alternative for modern browsers (IE11+) that provides jQuery-style syntax for manipulating the DOM. Utilizing modern browser features to minimize the codebase, developers can use the familiar chainable methods at a fraction of the file size. 100% feature parity with jQuery isn’t a goal, but Cash comes helpfully close, covering most day to day use cases.
6 KB minified and gzipped, which is even smaller than Zepto. Zepto’s whole point was a smaller jQuery, but it hasn’t been touched in a bunch of years, so there is that too.
I wonder how much smaller Cash would be if it dropped IE 11 support.
jQuery is still used on an absolute ton of sites, only just recently having peaked in usage and showing signs of decline. That must be because it comes on most WordPress sites, right?! That’s like 42% of all sites right there.
Anyway, if you tend to reach for jQuery just for some convenient APIs, Cash looks like a nice alternative. I don’t blame you either. Typing $ instead of document.querySelectorAll still feels good to me, not to mention all the other fanciness tucked behind that dollar sign function.
Also worth mentioning: if you’re looking to straight-up remove jQuery from a project, replace-jquery might be worth a look:
Automatically find jQuery methods from existing projects and generate vanilla js alternatives.
