Just because it's on the internet it doesn't mean it's true.

You might be confused how a CPU, memory, and I/O are interconnected. First, for an application to access data in memory, all it need to do is issue a MOV with indirect addressing. It might trigger a minor page fault which gets handled quickly by the OS. For an application to read data from disk, it must submit a request to the disk controller through the OS. I am ignoring a lot of details but that's all you need to reconsider the information in the links you shared.

Keep in mind that reading from memory is in the nanoseconds, while reading from NVME is in microseconds.