Despite Intel giving PCIe 4.0 the cold shoulder, UL Benchmarks has gone ahead with the launch of its PCIe bandwidth benchmark. The minute-long test is a synthetic scenario and even the creators of the test recognize that modern PC games are unlikely to be limited by the PCIe bandwidth.
https://www.notebookcheck.net/3DMark-Advanced-Edition-is-now-only-4-49-for-a-limited-time-to-accompany-new-PCIe-4-0-feature-benchmark.426486.0.html