According to external sources, Google has already designed a Quantum Computer that's much more powerful than its competitors (like IBM and other mainstream companies working on this).
This is wrong. It's wrong on many, many levels, but at the simplest level IBM has explained that Google have not reached so-called Quantum Supremacy.
From a
blog post by IBM:
In the paper, it is argued that their device reached quantum supremacy and that a state-of-the-art supercomputer would require approximately 10,000 years to perform the equivalent task. We argue that an ideal simulation of the same task can be performed on a classical system in 2.5 days and with far greater fidelity. This is in fact a conservative, worst-case estimate, and we expect that with additional refinements the classical cost of the simulation can be further reduced.
In other words, this new system is not the great leap forward that some lazy hack journalists would have you believe.
Further...
Anyone who tells you that this or any other quantum computer can brute force private keys doesn't know what they're talking about. There are more BTC private key combinations than there are atoms in the entire universe.