Nah Google doesn't pose a threat. Developers have realized the problem. The other day I was talking to an ex-BTC developer who said that the devs have already started looking into quantum resistant hashing. In a year or 2 we should start seeing the early versions of quantum resitant cryptogrpahy
In the first place it doesn't mean when we say quantum computing power, means powerful decryption of secured passwords. Quantum computers have their massive computing difference to the computing algorithms or patters we have on our pc which primarily responsible in encrypting and decrypting cryptocurrency. In addition, the hashing algorithm such as SHA256 is quite strong enough, though, there is a possibility it could be compromised by the quantum computers, but there are restrictions that quantum computers need to conform which make the cryptocurrency invulnerable to them.