Regardless of how advanced any hardware will become, there is still only one block per ~10 minutes.
If blocks are being found faster than every 10 minutes, the difficulty will rise to match the hardware so that it still remains one block every ~10 minutes.
What does that mean to you or me? Well, if you're still mining with a CPU or GPU, you already know what that means. For people who are using ASICs, they have an advantage.
Whether you are advantaged or disadvantaged, it has no affect on what a bitcoin is worth. And no affect on whether bitcoin is in any danger of being destroyed.
no man!!!
Bitcoin can come in danger if the quantum computer starts solving sha-256.
There is a theory that if we use quantum computer with sha-256 capabilities then it will solve the entire network in just a little bit of time.
If sha-256 is cracked by quantum computers, everything running on that would be compromised too. This includes all credit cards and most secure sites on the internet using SSH technology. They could also just upgrade to a better and more secure algorithm - sha-512 or whatever.
I am not a security expert, but I have read the information and understand the basics of the theory behind it. This has also been discussed before, and everyone agree that this is not an issue at all. Bitcoin is very flexible and the algorithms behind it is very robust.
Bring on the quantum computers, and see if they can do what no super computer have been able to do, up to this date. The mathematical calculations to crack a private key is staggering and beyond the combined computer power of all the computers on this planet.