We have been promised the light since the 1980s
Photonic interconnects have been the next big thing for about as long as I have been in the industry. Nvidia betting on them tells you less about optical maturity and more about how utterly we have exhausted what copper can do at these bandwidths. A thousand GPUs worth of data moved by light sounds brilliant until you remember every photonic link still needs electrical conversion at each end. The bottleneck does not disappear. It just gets a more expensive postcode.