OP's "don't believe" is a pure speculation at the moment. We know nothing about potentials of future technologies. If quantum computing become power enough to break the current ECDSA scheme and other algos involved then quantum resistant   cryptography will  take its place. The biggest problem  for scientists in the 17th century was how to clear the Earth from a layer of manure that will cover it in 100 years. That  problem disappeared after the horses were replaced by steam and an internal combustion engines.