USB3 activity detection
No. Or, yes, that would be easy to make, and it would constantly blink faster than your eye could recognize, because USB doesn't only consist of "big data transfers", but also of hundreds of status / bus arbitration transfers per second.

So without dedicated logic, it's impossible for your cable to tell "somethings happening on the bus, might be relevant, might not be" from "this is an ongoing USB data connection".