It's a great question and comes up a lot since it's such a natural thought. The answer is no and the main reason is network effects. In other words, first-mover advantage. From the network effect we obtain value and therefore security. If a new coin appeared with some killer feature which was actually sound, it would be added into, or implemented on top of Bitcoin. That being said we're always wise to be cautious and stay aware of what's going on out there in the realm of fundamental and proven advances. Over time you tend to curate a collection of experts on the various pieces to help evaluate new developments.