Wow, this thread made me realize that I have become one of those people who inexplicably do not have a collection. I always thought those gamers were the odd ones, but here I am. A year ago, I had about 40 games each of NES, SNES, and PSone, along with a dozen each of 3DS, Wii, and Wii U. Sold... all sold earlier this year. I had acquired those games over the past ten years and had my fun with them, some of the best gaming of my life. I looked at my shelves of games, thousands of dollars worth*, and felt it was time to pass it on.
I am just done with old games, instead focusing on the current generation, something I haven't done since the N64. My "collection" now consists of a handful of Switch and PS4 games, although admittedly, I still have the shelf of PS3 games that I will get to eventually. I am at the point where, if I am not going to play something again, I sell or trade it towards something new. My urge to "collect" is gone.
*net totals after sales were approximately NES $1500, SNES $3500, PSone $4000