I agree that a browser 100% up to modern standards would likely be ridiculously slow, especially on 68k machines. (Personally, I'd much rather browse on a modern computer anyway. The ability to boot up IBrowse and handle online banking might be cool novelty fun, but torturing myself and my Amigas with something like Firefox sounds terrible.) From my perspective, IBrowse strikes a nice balance between being reasonably capable of handling the "basics", while retaining (very) good performance.
There's a somewhat up-to-date 68k version of ICab, and while I admittedly know exactly _nothing_ about programming (outside of some pretty wicked BASIC skillz, LOL), perhaps an amiga port of that would be easier than shooting for the stars with something like Firefox.
