There are certainly downsides to hording data. At the very least, information takes up space. It also tends to suck up mental bandwidth: you have to keep organizing, de-duplicating, and migrating to newer formats. It's much easier to just delete it. Just like it's much easier to throw old ratty tshirts. IMO, data hoarding is just as much of a mental disorder as hoarding physical stuff.

This idea that all information must be preserved for forever is also at odds with privacy. See, e.g., the right to be forgotten.