Why isn't PCIE 4.0 certified riser cable a thing now?

Skylinestar:

Why isn't PCIE 4.0 certified riser cable a thing now?

Most likely the extra length of the ribbon cable completely messes up faster timings of signals so not easy to do. Anyway if I read this right, the entire GPU is shifted inwards maybe 4cm so that there is space inside case for plugging in DP cables... so does this mean there is even less room on right of GPU, and already long cards will no longer fit in smaller cases?

geogan:

Most likely the extra length of the ribbon cable completely messes up faster timings of signals so not easy to do. Anyway if I read this right, the entire GPU is shifted inwards maybe 4cm so that there is space inside case for plugging in DP cables... so does this mean there is even less room on right of GPU, and already long cards will no longer fit in smaller cases?

There are PCI-E 4.0 certified riser cables which are 25cm long available, but they cost as much as the bracket on it's own. Yes, you are correct that the bracket takes around 4cm clearance.

So i assume this does not work with cases that are flipped where the cpu at the bottom.