Web app development using NodeJS without reactJS and any framework.
Redirect loads the same page and the client use history API or load page section based on URL state. Look for react-router alternates to manage pages, micro UI can be used to load a limit set of JS different bundles for different pages.
Different complex HTML DOM templates can be written in sever side fragments or (PHP, JSP, etc.) The templates can be included on the page wherever required.
No need to maintain state or variables only edit parameters are needed, render/rerender only works to add syntactical complexity.
Assess your page and see its complexity to decide whether it needs heavy DOM manipulations to avoid such design which requires DOM manipulations. If still needed, add a react section to the page, but don't go ahead and design the whole page using react.
Here is an example of webpack setup without any framework
