Hardware

I think you're overstating the impact of this development. The US, PRC, EU, and Japan national programs are sticking to systems in supercomputer centers, universities, and government facilities for the foreseeable future. The main reasons for this are practicality (how exactly does one migrate several PB of data in the cloud, for instance), security, and politics. Thus, I'd expect things at the top-end of supercomputing to stay more or less the same. Industrial users who want cheap supercomputing occasionally might be pleased, but that's not what the leading supercomputing centers do.

Not really, no. Fugaku is a pretty efficient system, more so than its competitors. Even if it's going to be outclassed by others being larger scale, its still more efficient.