Yeah - I think the confusion was that, at the time of the iPhone release, for most people Rich Web Apps primarily meant Adobe Flash, and Jobs was adamant at not supporting that (which would have required an Adobe plug-in for Safari). Android briefly supported Flash (Apple is doomed!!!) but turns out - apart from security concerns - it just didn't work very well and rapidly got dropped.
Browsers did support Javascript/DOM - but Microsoft Internet Explorer was still king on the desktop and was gratuitously incompatible with standards, which was one of the reasons why Flash became dominant. Modern "Progressive Web App" support is now vastly improved and more portable - although Safari now tends to be the problem child when trying to write portable web apps (Apple dragged their feet on some new 'standard' browser features) it's nowhere near as problematic as IE.
The death of Flash was a good thing in the long term, but directly after the iPhone launch and the early years of Android "state of the art" Javascript/DOM webapps couldn't really compete with native Apps.