This is wrong, please check what DGX is.

DGX is a complete data center from Nvidia where Nvidia is the supplier of everything themselves:

- CPU+GPU from Nvidia - Rack from Nvidia - Interconnects + networking from Nvidia - SW from OS to application framework from Nvidia

The only thing Nvidia really needs partners with DGX is memory (RAM + SSD).

One reason Nvidia's margins are so high is because they provide the whole data center so while competition has to split margins (AMD/Intel + SMCI/DELL + Broadcom/Arista + Cray/HPE).