I wouldn't say this is 100% bound to happen as people sometimes are quite stubborn in supporting something and something should be clear - while both Bitcoin and other blockchains have their utility and utility is definitely a factor, what really gives any currency, investment tool or resource value above all is people's trust. And people often misplace that ;)
But it's only natural that Bitcoin will become obsolete sooner or later, after all it's really the first major attempt at this and aren't quantum computers coming to get us sooner or later anyway?