In almost all cases the back swipe in the spa resets you to the top of the page, navigating out of the app and back in doesn’t work, etc. It’s really hard to build a multi page spa that feels good.
It reminded me of the time when I joined Wikia (now Fandom) back in, I think it was 2006. One of the first things that landed on my desk was (I can't recall the context) deeplinking.
And I remember being completely flabergasted, as I came Flash/games background, and for us that problem was completely solved for at least 4 years at the time (asual swfaddress package). I felt kind of stupid having to introduce that concept to much more senior engineers that I was at the time.
https://dev.to/cyco130/how-to-get-client-side-navigation-rig...
In Tanstack Router it's a boolean you set when creating the router. The documentation nicely lays out what's being done under the hood, and it's quite a bit.[1] I wouldn't try that at home.
In React Router you just chuck a <ScrollRestoration /> somewhere in your DOM.[2]
[1]: https://tanstack.com/router/v1/docs/framework/react/guide/sc...
[2]: https://reactrouter.com/6.30.1/components/scroll-restoration