There are a lot of flaws with bitcoins, and it pioneered cryptocurrency. But do we still dial up to BBSes today? Use gopher? No, it has being replaced by the world wide web. Bitcoins will be replaced, don't put your life savings in.
The World Wide Web as we know it today is the product of layers upon layers of protocols added over time to address various problems, so, you know, you don't always just toss out the base and start over.