"Sometimes".

I will keep a console if the games I want aren't on another system and look/play better than the original.
Case in point: Sold my Nintendo 64 as games like Perfect Dark, Ocarina of Time, Lylat Wars were found on other devices. (3DS and Xbox 360.)

No, it's a long tale of stupid decisions. I still own a WiiU, Switch, PS3, PS4, New 3DS XL, GBA SP and a PSP.

I don't just keep them I play them and seek out more retro systems. I collect so very much yes.

I don't have many older consoles/handhelds but I have kept them all so far.
PS1, PS2, PS3, PSP, Gameboy Colour and Advanced, DS, OG Xbox, Sega Genesis and Saturn are all still in my possession.

The only thing I don't have is my Atari 2600. I left that at my dads house: only to be seen again as a center piece (along with other retro systems) on a table when my little brother graduated.

I still have everything back to my atari 2600 all in perfectly playable condition and along with a huge library of games for each system through the years. to my left is 5 stacks of GC games as tall as a person and in my sitting room are boxes of alphabetised X360 games.

Yes, i keep my old gaming consoles, but not all i'm gonna play them consoles except for Dreamcast & Saturn, these are the only two consoles i play them.

Play it for a while until you get tired of it, then sell it.  

What am I keeping it for?

I get rid of them..... truth be told not just consoles. I get rid of anything that i do not use for up to a month.

I sell all of my old systems and nearly all games. I see no reason to keep them, once they get to a point where I know I won't play them again.

For many years, maybe 2000 through 2014, I spent next to nothing gaming, though I played fairly regularly. I never bought games anywhere near launch, so I was generally spending less than $20 per game. Then, as soon as I was done with a game, I resold it. The only exceptions were Halo games, which I usually bought at launch. I estimate that my net gaming expenses were about $100 per year, excluding an occasional console purchase.

In 2014, with the release of Mario Kart 8, and the replayability of that game, I broke my "rule". I purchased it at launch, and never resold it (I still play it occasionally). Then I purchased Destiny at launch, and never resold it. So, I threw out my rule book. I still sell most games when I'm done with them. But, since I buy more games at or near launch, I lose a lot more money on them. I'm probably spending $300 to $400 net annually on games these days.