It's all at the big cloud service providers. Not as much focused on the physical network (as originally imagined), but in the overlay networks. Seethe various DPUs like Intel IPU, Nvidia/Mellanox Bluefield, etc. Nvidia DOCA even uses OvS as the sort of example out of the box software to implement networking on Bluefield. When your controller is Arm cores 5 cm away on the same PCB doing per connection setup is no longer as absurd ;)