Except "the cloud" at that point was specifically just a large number of normal desktop-architecture machines. Specifically not a new ISA or machine type, running entirely normal OS and libraries. At no point did Google or Amazon or Microsoft make people port/rewrite all of their software for cloud deployment.
At the point that Google's "bunch of cheap computers" was new, CPU performance was still rapidly improving. The competition was traditional "big iron" or mainframe systems, and the novelty was in achieving high reliability through distribution, rather than building on fault-tolerant hardware. By the time the rate of CPU performance improvement was slowing in the mid 2000s, large clusters smaller machines were omnipresent in supercomputing and HPC applications.
The real "new architecture(s)" of this century are GPUs, but much of the development and success of them is the result of many iterations and a lot of convergent evolution.