>performance is poor they were designed for batch.

That's once again an oversimplification, performance is excellent for the intended workload.

I've briefly encountered mainframes in the 90s. I thought it was a perfect analogy to AWS where "intelligence" is in the center and we're just piping stuff over the network for AWS to compute. I don't understand how selfhosted/self-provisioned servers is supposedly comparable to a mainframe, on the contrary.

> It's 2022 and we're about to rediscover something we know for 40 years already: mainframes are freaking expensive.

My interpretation: AWS is freaking expensive, AWS is in the center performing all computations; AWS is the mainframe we can well do without.

Of course AWS is the mainframe in this analogy! It's a huge throughput- and reliability-optimized overhyped crazy expensive server that you hire someone else to run for you. It's designed the same way, with dedicated storage, compute and backplane servers. Even the discourse is the same to the 80s: "why we have to rent a $$$ monster when a $ commodity server outperforms it". How is this not obvious is beyond me.