Failing is too strong a word. It is and will be on the decline versus newer tech. A lot has been learned since 2008 and it seems very likely its better to apply that in a new and fresh system. Ironically Bitcoiners aren't necessarily up to date with all that new research.
Hard to tell whether Bitcoin is a VHS vs Betamax situation where the best technology doesn't actually win, or a Myspace vs Facebook thing where the old one gets disrupted by new.