> Then you have a shitty app.
This feels a lot like you're making a “No True Scotsman” argument. The behaviour you're saying doesn't / shouldn't happen has been the defining characteristic of SPAs since the beginning and it's still immediately visible on most of them as soon as you have a less than perfect high-speed internet connection. If statistically nobody except the Wordle developer can make something which handles crappy WiFi the problem requires more than just saying someone is a bad developer.
Then you have a shitty app.
Between localstorage and indexdb - unless you're literally out of disk and having storage being evicted, then if you've loaded my app once (and I mean once, not once this browser session) then I have data in cache.
Basically - don't blame SPAs, blame developers for assuming that the same "request the data every page view" paradigm is still in play.
It's not, and storage is insanely cheap.