The primary purpose for a collapsable stock is for users wearing body armor, heavy clothing, lots of other gear = it makes the rifle instantly adjustable for a better cheek mount, based upon what one is currently wearing.
The second and third purposes would be to make it more compact for use in vehicles/boats/etc and also to reduce the weight.
For the lighter weight and shorter reasons, it also appeals to smaller sized people.
If you were just in normal clothing all the time, the solid fixed stock is much better. This would be the best for competition shooters, casual range use shooters, etc. Think of the last time you saw shooters in competition extending their stocks just prior to the shoot - it doesn't happen. The fixed stocks, with or without semi-permanent adjustment add ons, are the best for a consistent length of pull, cheek weld, shoulder contact mount and aid in proper firing grip placement.
The collapsable stocks are the winner for "fighting guns" that see use in combat, law enforcement, always changing defensive situations.
If you are just considering getting it to make it shorter, so there's more room in the safe - it won't make any real noticeable difference - and if your safe is that full, then I'd suggest that it's time for another safe!