Hard drives that aren’t used will get data errors over time. Usually for data storage this is counteracted with what’s called a “scrub” every so often (like few months). This just means the whole drive content is read, and the drive itself will figure out if any areas have a “weak signal”, and just rewrite that part.

Having only 1 drive without any mirror and without any way to detect potential errors (let alone a way to correct them) is a recipe for disaster.