If the state is coming from the server-side database, and has to be persisted there, you'll still need to fetch it, and save it. If there's some transient stat

If the state is coming from the server-side database, and has to be persisted there, you'll still need to fetch it, and save it. If there's some transient state that belongs to the web page, vanilla JS is just as capable as a SPA at managing that - and it's just as prone to losing unsaved changes.