An ARM supercomputer was already #1 in 2020 [0]. The Japanese Fugaku is also notable because it doesn't use GPUs to achieve high performance, but rather wide vector units on the CPU.
I'm sorry but being #1 or even in the top 500 matters very little because most of it is due to how many units are installed in the cluster including networking, memory, architecture, cooling, etc. I mean, if you didn't reach top 500, just add more units into the cluster until you do. Don't get me wrong because there is a lot of tech involved but we are talking about distributed processing instead of the performance and efficiency of a single processor.