I don’t understand your position at all. If you want to open your documents in a decade or more, redesigning a “cleaner” PDF would only make that less likely.

I don’t understand your position at all. If you want to open your documents in a decade or more, redesigning a “cleaner” PDF would only make that less likely. If you want something cleaner than PDF, then XPS is already here. I don’t understand what scenario we’d have where designing a completely new format would give us better software support. So, the reason I’d see for designing a new format is if neither XPS nor PDF are good enough for some application.