So who is the real market leader?
Given that the majority of companies I have worked with have started their generalized virtualization journey in the old days with VMware on vanilla x86-64 servers, I would suspect the majority simply moved on to VMware's vSAN for their "hyperconverged" platform, mainly because it meant they re-used their old vSphere skills. So I suspect the figures for the HCI market are really the tip of the iceberg, with the DIY efforts using COTS servers and storage being the much larger part hidden beneath the waves.