You can answer all of these questions by running a filesystem or system call trace on Chrome processes, which will be more accurate than listening for the file access with your ears. Without such evidence you are jumping to wild conclusions.

On macOS, use Activity Monitor to inspect the process and it will show you a list of open files. You can also use lsof, strace, dtrace, depending on your OS. I don’t know about Windows.

You could also try defragging your hard drive.