We're currently at Typesetter version 5.2-rc (release candidate) on GitHub.
TS 5.2 comes with Bootstrap 4.4 as well as a lot of other new things
We will continue to support Bootstrap 3 in future versions because many existing websites are using BS3 based themes. That's why we still use jQuery 2 - Bootstrap 3 is not compatible with jQuery 3.x.
For jQuery itself: Typesetter's admin JS is jQuery, alomst every single par of it. Same applies to finder (the file manager) and some other thirdparty components. Almost every Typersetter plugin I know uses jQuery. It's simply everywhere.
So, to answer your question: Stripping off jQuery from Typesetter (and use sth. else instead, like react, angular, vue, you name it) would be a rewrite of the entire client side and large parts of the backend. It would break all backward compatibility, lose some themes and all plugins. Even if it looked the same, it would be a completely new CMS.
If I had the time and knowledge to do this, I'd rather start over.
2 days ago