jQuery is fine to add some client side interactivity on websites, but it doesn't provide enough structure, automation and reusability tools when it comes to building SPAs. You will eventually have to write your own framework on top of jQuery, which basically makes you reinvent Angular, React, Vue and friends. If you are building a SPA, I'd definitely recommend you to check out one of the existing solutions instead of writing it from scratch. Telling you this based on my experience of building SPAs with jQuery before Backbone and Angular were even a thing.
“If it ain't broke, don't fix it.”