I think user expectations (and/or product/UX expectations) have changed along with the rise of the SPA. In the days of server-rendered apps before SPA was a th

I think user expectations (and/or product/UX expectations) have changed along with the rise of the SPA. In the days of server-rendered apps before SPA was a thing, the answer to all of those questions would've been some version of "You don't," followed by "Why would anyone expect a website to work offline, or be fast when the network is slow?" But SPAs are in a sort of "uncanny valley" where they sorta look and feel like native apps and users expect them to behave like native apps but doing that is much more work than building a simple webapp. There's a bit of cargo culting here too, I think. Not everything needs offline support and instant updates from Firebase. But $fancy_native_mobile_app has it, so our imitation SPA must too.