I've been pretty skeptical about SPAs but having tried out Svelte for a few side projects, I have to admin I was probably directing my skepticism to the wrong thing, probably React was the cause of my dislike for SPAs. Svelte looks really awesome and the simplicity it brings back is invaluable. I really wish it takes off, for real. Looks very promising.
What bits were misdirected? What worries did you have?
Things such as redux, rxjs, observables, thunks, etc really put me off when you compare that to just MVC with Rails for example, plus most applications I worked with React were just forms anyway, with some fancy controls/widgets on top.
Not having a clear way, even today with Next, to load data (client side, without doing SSR) before a route transition happens (which leads to spinners everywhere), and now the solution seems to be all the server components, concurrent mode, suspense, etc, etc which to me is just mind blowing how complex things became.
Also hooks which conceptually they make a lot of sense and I like them, but then you have to do all the dependencies tracking manually, they have a lot of gotchas (async in useEffect, ordering, etc).
The "rerendering of everything" and the need for manual memo, useMemo, useCallback, etc and the whole "don't optimize it until you need it" (guess what, a my company as in many others it never was a product priority to make it fast).
Now, take the good parts of the approach, remove all these complications, and you have a very nice and clean approach to do web apps. To me that is what Svelte brings back.