^I don't even think it's fair/accurate to compared bitcoin to other cryptocurrencies today. Bitcoin and the broader cryptocurrencies are in different categories functionality-wise and usecase-wise, the only similarity is both using blockchains.
Plus, it's very likely that the general Bitcoin user will also rely on Altcoins for specific needs. For example, as a way of transacting quicker, but with less security or a way of contributing to projects which are testing the boundaries, and new technologies which could potentially either be introduced to Bitcoin once proven or used alongside it on a side chain. I'm only invested in Bitcoin, however I don't disagree that we'll likely need other cryptocurrencies to fill the gap, that Bitcoin either won't ever fill or doesn't want too for the time being.
There's plenty of interesting ideas out there. However, most of the time the execution is rather lacking.