My impression for the last ~10+ years is that you could not depend on index db in safari, not for heavy use cases, and doubly so for ios and there was not a viable alternative whenever I checked.
I would be happy to know that things are looking better for PWAs on ios though if things are now viable.
Thanks for the additional background, I'll dig into that! FYI, based in part on our exchange, I created pwascore.com to scratch the itch of wanting a reasonably-objective "score" for browser PWA support.
My impression for the last ~10+ years is that you could not depend on index db in safari, not for heavy use cases, and doubly so for ios and there was not a viable alternative whenever I checked.
I would be happy to know that things are looking better for PWAs on ios though if things are now viable.