rails-ujs has been around for a long time (I want to say since the Rails 3 era, but not certain), the change here is to move that from jQuery to vanilla JS, jus

rails-ujs has been around for a long time (I want to say since the Rails 3 era, but not certain), the change here is to move that from jQuery to vanilla JS, just as back in the day it was once migrated from Prototype.js to jQuery