>no 240W USB-PD chip has ever gone into production

This is because the cross-sectional-area of the conductor would create an inflexible cable – and even then the connector (even though rated) could never handle a sustained 240W in the real world.

Fires. Fires everywhere... this is why no 240W chip exists.

src: electrician

I think you’re overthinking the bottleneck side of things: RAM to RAM would be sufficient to capture if the cable is capable of 40Gbps.

All an end user cares about is if the cable is the bottleneck, if you think you have known-good devices. If I have a MacBook and a good NVMe enclosure, I want to know if my cable is fast enough, rather than have it quietly fall back to 3.2 or worse.