> Honestly don't know what people think they are gaining with a heavy frontend.
True, but (I repeat myself here), it depends on what kind of website we are talking about. For instance, a data-heavy SPA that workers use the whole day (like a CRM) is at least perceptually faster and more user friendly compared to the same thing but with traditional whole page reloads.
I am open for suggestions, but anything wanting to give a desktop like experience is going to be complex. Like the user clicks a button, now widget a1 » a1.3 » a1.3.2 » a1.3.2.2 should be in an "open state", while widget b1 » b1.2 » b1.2.1 needs to be in "disabled state" and widget c3 » c4 » c5 shows a status message.
