When I first played Witcher 3 I was like “why the fuck would I play a card game in this vibrant, immersive, story-rich action-adventure game?” and then somewhere along the lines I got to the point where I was running around the whole game world ready to suck dick for Gwent cards. I have no idea how they got me, but Gwent is easily the best game-within-a-game I’ve ever played.
Because you didn't have to run around collecting dice and then use a spreadsheet to organize the dice into an optimized dice stack meta and then lose anyway when you don't draw the right dice from your pile of random dice
I played Gwent at every opportunity in the Witcher game and thought I'd love the stand-alone Gwent. Boy was I wrong.
The mini game was simple enough to learn and not that hard to master. Gwent stand-alone is just too complex to have some simple fun with it.