what's the big difference between single and multi mode fiber? Why is it scalable but multi-mode isn't?
https://www.tlnetworx.com/blogs/news/single-mode-vs-multimod...
And to be clear, there will be hacks that scale MMF a bit, but it’s not really “infinitely” scalable due to relatively poor attenuation and light mode. Keep in mind, there isn’t one MMF spec, there’s many: eg. OM1 through OM4