Ever since I got a new gaming laptop and a Nintendo Switch, I've found some of my PS4 and Vita games migrating to them. This isn't an entirely bad thing, as it frees up storage on my PlayStation platforms, (where storage is often tight anyway), but some of it just boils down to the fact that I want a lot of my favorite games on more portable platforms.
Rogue Legacy, Transistor and Dark Souls recently came out on the Switch and, despite having them on PS4, I just couldn't help but want them for the Switch. I imported Okami for Switch even though digital would have been fine and I had it on PS4, but the Zelda-like nature of Okami just feels right on a Nintendo system. I wanted to play these games during my lunch breaks at work. A lot of games I have for PlayStation platforms just feel better on the Switch sometimes.
That's not to say my PlayStation platforms aren't home to repeat purchases. If Castlevania: Symphony of Night appears anywhere, I'll get it. I play the game nearly every year as it is, so having even a mildly updated version of the game is more than welcome. I have also owned Metal Gear Solid 3 and Super Metroid across various platforms for this same reason. It's just a matter of time before I replay these amazing classics and sometimes discover new things about them.