Microsoft and Nutanix have had a hyperconverged architecture for over a decade. Oxide is mostly an alternative to Nutanix or other soup-to-nuts private clouds.
Oxide is a really nice platform. I keep trying to manipulate things at work to justify the buy in (I really want to play wiht their stuff), but they aren't going for it.
Afaik nutanix doesn't sell a custom rack, running custom firmware, preloaded with their software though.
The first attempts at hyperconverged were very hardware focused and kinda meh. Nutanix is the best example - they pioneered hyperconverged hardware but the firmware/software was extremely average. Oxide are the first to say "it should just feel like cloud, except you own it" and building for that.