Actually not IO performance, but mostly CPU. Last time I tested (which admittedly was about a year ago), an AWS ES cluster was about 20% slower than a self-made cluster with the same instance types. Given that AWS ES clusters still cannot use C5 instances, which offer FAR better cost/$, the performance disparity today might be even larger.

I can also launch an Elasticsearch cluster myself in about 2 minutes via terraform, so 20 minutes is not super impressive.

That said I recognize Elasticsearch is actually quite a finicky beast to set up, and my setup only has to deal with the needs I have, and probably would be set up horribly for certain other people. I can see how a hosted system that has to deal with all the weird edge-cases of a few thousand customers would take longer to set things up.