There are as many goals in collecting as there are collectors. Many collectors do not want to use their items as some of the items are pushing 40 years old and will not last forever. Every disc read and manual flip subtracts from their life. This may all sound silly, but compare this to Silent Era films. 75% of films from that time period are gone, forever [0]. We are still in the beginnings of the medium of games and we could fall prey to the same mistakes as previous mediums. Some section of the medium must get locked down so that future historians can study them in as much detail as possible.
One advantage we have is the rapid increase in digital storage space means that many of these will not be lost if we can get them imaged, many people can each have a copy of almost every known NES game in only a few hundred megabytes.
What will be lost are the manuals, boxes, cloth maps. little post card inserts for some random warranty or club, and most importantly, the physical feel of all these things. That is the primary thing collectors want to preserve.
I like buying used (not collectible) books, and once in a while I find artifacts used as bookmarks - a store receipt, an airline boarding pass, a newspaper clipping. These objects are fascinating to me; I'm briefly transported into the world of the person who originally bought the book and how different it seems from that of today. The details of the 'bonus item' are like clues to the identity of the mysterious reader that preceded me, whose identity and trajectory are as entertaining to speculate about as as the fictional or theoretical subject matter of the book itself.
Over time, everything becomes an antique; competitive collecting (for well-defined subsets of items in a niche market) is arguably a way for people of similar temperaments and taste to locate each other socially, but the more effort they invest in this (by developing catalogues or price histories of their favored artifacts) the more likely they are to be crowded out speculators who recognize the hallmarks of an asset class without especially caring what they are attached to.
Also, the packaging apparently wasn't identical. It was hand-cut at least some of the time and imperfect.