Singlemode's biggest weakness is alignment, optics, and a big change for a single dust particle to do a double digit decibel drop.
Either terminations will have to be done with some abuse proofing ferrule with a built-in lens, or every optical cable have to be active, with a transmitter glued to it.
The later in comparison to first, solves the issue in its entirety, and is not that much of a crazy proposition today.
Even the most fancy laser chips like EAM, and MZI modulated ones, can be made for cents if the competition will made vendors to drop prices.
Right - you can buy these right now: https://www.corning.com/optical-cables-by-corning/worldwide/...
1. Single mode fibre already costs less than high high frequency cabling.
2. A standard written from scratch can move all smart electronics, and even some passives from the transceiver into the device.
3. The moment a transceiver turns into a standardised single chip device, economies of scale turn enormous.
4. Optics can be simplified for direct attach devices.
5. Cheapest transceivers sets + cabling for single mode 10G ethernet already cost less than $10 wholesale.