It is unfair to compare the careless jQuery spaghetti that was pretty common time ago with a client side framework such as React regarding maintainability. If you put some effort (which I'm convinced is a lot less than the effort we put to build SPAs) into doing the "sprinkles" right, it can be as maintainable as the SPA or even more, with the added benefit of not sending so much crap to the end user. There are modern approaches to this (Turbolinks, stimulus, Unpoly, Intercooler, etc...), no need to do manual JQuery manipulation anymore. Pair it with Node, and you still have a pure JavaScript solution without wasting the user's CPU, memory and patience.