The thing about Gwent is that it is clearly a well made (mini-)game. Otherweise, people wouldn't be playing it so much and it wouldn't have become as popular as it did. That said, I'm with voodoo ray. I'm not that big a fan of those games inside games that I spend hours playing them. I'll do what's needed and then just get on with the proper game. With Gwent I had an additional issue and that was having to look for cards and that's my other pet peeve in games. I just cannot be arsed looking everywhere for stuff to complete a collection or in the case of Gwent to get more cards. I just feel it's a waste of time. And again, I know I'm in a minority there, because clearly modern games also have a lot of stuff for completionists. I just don't care about whether I've done 100 percent of a game, when 40 of those 100 percent consist of doing boring stuff like running through the world picking up special items or getting achievements where you have to do stuff a certain way.
