>> if a giant production like The Witcher 3 can profit this way, any card game can.
In theory yes, but in practice a CCG needs to be updated a lot and for years to be viable, while a game like Witcher doesn't. Would you pay $60 for the CCG game where you can't add new cards? Charging as you go seems to fit the model of player activity and developer activity.
There are many other online & well-updated games though, there's an entire genre of them: MMORPGs, yet they came up with quite sensible/much less predatory business models, at least compared to CCGs.
Some have buy2play with bi-yearly expansions & cosmetic shops, some have subscription-based models, and others, mostly asian fp2 ones have a more a la carte approach, yet even those would pale in comparison to CCG greed. Those games get entire new gameplay modes, quests, worlds added via updates, yet they can manage. I see no reason why a CCG can't.
In theory yes, but in practice a CCG needs to be updated a lot and for years to be viable, while a game like Witcher doesn't. Would you pay $60 for the CCG game where you can't add new cards? Charging as you go seems to fit the model of player activity and developer activity.