Aren’t you building pyramids with grains of sand if you don’t use a framework? I can’t imagine how much manual work it would take to drop Vue.
I have a personal project that's about 30k lines of jQuery on one page - if you want to see an example of what that looks like:
Over the weekend AWS reported my instance health went to Bad for a bit not sure why.
https://github.com/hyperandroid/CAAT
If it wasn't for that I would have never been able to stitch together a project as difficult as this.