Whilst that's true, current-gen PCIe 4.0 drives and CPUs aren't actually fast enough to achieve PCIe 4.0 speeds when using them for tasks and as an OS drive.
The point I'm making is that the controllers, CPU, OS scheduler, other storage overheads mean that you never see gen 4 speeds when using it as a single drive. Almost everything is compressed these days and has a CPU/RAM/OS overhead. I'm not even including encryption or realtime AV/Malware scanning which is often enabled for consumers. Even if you're working with large files and reading/writing them to the drive on a regular basis, there's far more at play than the storage bandwidth - you can have perfmon open with your SSD, run some read/write heavy workloads and you'll rarely get speeds beyond PCIe 3.0 x2, if ever. In a PCIe 3.0 system, with a fast gen3 drive, the storage bandwidth is no longer the biggest bottleneck - that burden rests mostly on CPU/OS scheduler for anything outside of non-windows proprietary datacenter/compute nodes.
The only way to see PCIe 4.0 speeds on a PCIe 4.0 drive is to transfer data to/from another PCIe 4.0 drive, or perform a raw,large,sequential data read/write - that's pretty much limited to a small subset of video editing operations - for the consumer workloads at least.