A big downside to this on-package combination is the inevitable degradation and destruction of some I/O. Take optics for example, if your SFP transceiver has a

A big downside to this on-package combination is the inevitable degradation and destruction of some I/O. Take optics for example, if your SFP transceiver has a bad source or detector, you can replace it and keep going. If your on-package optics chiplet dies, you're simply stuck with no optics and either have to replace the entire package or maybe even the entire device.