Additionally, found this recent post going into why Safari is hot garbage. https://infrequently.org/2021/04/progress-delayed/
While the File System Access API is still being developed, I'm not holding my breath for it to appear on iOS. To be fair, it isn't supported yet on mobile Chrome (for Android obviously), but I expect it will be added quickly after the v1 of the API is finalized. I expect it will either never appear on iOS or it will take 5+ years from now...
You'll be sitting pretty on standards, or you'll be able to just target Chrome and forget about standards?
I’m told Gecko is a lot better now though.
One thing that WebKit does better than other browsers on OSX is hooking into the native rendering APIs. That’s something that Firefox does a shoddy job at.
It really gives management no opportunity to stand still on this anymore.