Apple's monopoly combined with its underinvestment in WebKit is definitely the main reason why web apps are subpar compared to native at the moment.
No, pretty sure that's not the main reason they're subpar compared to native.
Hell, so's Java, and that's way better-positioned to not-suck relative to native than webtech is, and it's been in that game far longer.
(Cue in "but they are underpowered devices in poor countries")