I'm only partway through reading the blog, but this and other errors I've spotted so far make me suspect the accuracy of the blog's analysis.
It looks like the author just went to https://cloud.google.com/compute/vm-instance-pricing#memory-... under the assumption that "memory-optimized" was what they needed, not realizing that "memory-optimized" is for truly ridiculous workloads with terabytes of RAM.
For "compute optimized" they're comparing ARM Graviton2 ("price performance optimized") AWS instances (I don't know where; I can't find any that cost >$0.2/hr) in to 3.8GHz Intel Cascade Lake ("highest performance per core") GCP instances... in LA.
For Google Cloud, the N2 machine family is actually quite expensive, and I tend to avoid them if possible. Rather, I use the E2 series for smaller machines, and the N2D series if I need a machine bigger than E2's size limits.
For us-west2, an e2-highmem-4 instance has 4 vCPUs and 32 GB of RAM, but costs only $0.217148 per hour.
and this is from the so-called cloud experts
edit: lol. downvotes. you suck google.
> n2-highmem-4 4 32GB $0.262028
Which turns out to be the cheapest price and that is not even preemptible which is $0.06356