I think it’s important to note, that it does not matter whether or not quantum is just around the corner, or decades away. It will arrive. The sooner it’s resolved the better. Indeed another Crypto besides Bitcoin may solve the problem sooner. If that should happen, then most likely, a lot of people might see that as being a better place to store their wealth instead of worrying whether or not Bitcoin will reach consensus on a solution. That could be Bitcoins problem before quantum ever arrives.