While I'm fully supportive of making a choice to not use current trendy frameworks... putting out a jQuery-based design system in 2020 doesn't feel like it is going to find a large target audience.
JQuery is like the PHP of front-end - inexpensive to build with, easy to use and loads of information available on stackoverflow.
Get over yourself. 75% of top 10 million websites still use. Heck Wordpress and Drupal still use. It's still relevant.