nothing stops cable makers from making the same for DP

In fact I’ve used a 100 foot fiber optic DisplayPort cable that I “just bought” on Amazon, admittedly for a LOT of money (like, I think it was about $100 USD, 3 years ago or so).

That's not actually such a bad price. I didn't know they even made these - cool!

Huh, I thought I had mine earlier. Mine was from May 2021. They were very very new and had very few reviews, and it was $56. For a 100' fiber optic cable that promised 8k60 and was light.

This cable is absurdly long. I have no idea how to coil it nicely. At my last place I had three stories, and would sometimes just dangle most of it down to the ground then wind it up from the roof.

I just wish they sold the transceivers separately from the fiber. Being able to use any random length of cheap off-the-shelf SMF/MMF fiber would be so much more convenient than having to get a custom one-off cable.

They exist for medium-speed HDMI (see for example [0]), but I haven't seen them for modern high-speed DP yet.

https://www.amazon.com/Converter-Extender-Transceiver-module...

You say it's a LOT, but it's about the same cost as a much much shorter USB 4.0 cable. (Granted, it also has to be able to carry 240W.)

I hate noise from the PC, so I've sited my PC under the desk at the opposite end of the room to where I sit (so about 3.5m away). I have a pair of 5m DP cables running to my 2 ultrawide monitors without any problems at all, so it seems if you buy decent cables it just works with DP too.

The only potential issue is that they seem to be slow waking up from sleep. I've never been interested enough to investigate if moving the PC closer with shorter cables fixes that, or whether it's just an issue with having 2 monitors. I think the underlying cause is actually just because it's Windows and that one monitor (they're supposed to be identical) seems to wake up earlier than the other, so it briefly flashes on, then goes black while it reconfigures for 2 screens and then on again.

But anyway, my 5m cable runs seem fine. They weren't especially expensive nor especially cheap cables, IIRC around 10-15 GBP each.