RTX 4000 isn't even data-center grade - it's workstation/pro segment. This is an important difference, as some server vendors (such as Dell) will not validate the workstation segment to run in their servers.

The segmentation is a huge mess from NVIDIA. Consumer grade GPUs aren't supposed to be run in data-center / compute (forbidden by EULA) and the workstation GPUs are in a weird middleground limbo, being many times more expensive, but not exactly attractive for server use for the above reasons.