OCP and Oxide two different but not exclusive approaches.
There are vendors providing different levels of integration, including groups that will ship you turneky systems akin to Oxide (or AWS Outpost). Those might depend on OCP Standards to provide higher level of integration than integrating normal HW solutions. Starts at integrating somewhat individual components, going through fill racks, to entire data center standards or designs for Modular Data Centers which you can load onto a truck, deliver to location, hook up and have them working (some might remember Sun containerised datacenter thing, which arguably reminds me of bigger Oxide rack in some ways)
Similarly some bits designed for OCP (or hosted by OCP) contribute to wider environment, like OpenBMC, OCP Mezzanine cards