But I thought nobody wanted the game key cards.

Nobody with taste wants game key cards.  8)

Hey, if Pokemon fans want to hasten the death of actual game ownership, that's on them. Just don't come crying to the rest of us once stuff gets de-listed and services shut down.

As for the news itself, from all accounts this is the rare actual good Pokemon game these days, since it was made by someone other than Game Freak. We should always champion when a good game sells well. Doesn't interest me in the slightest, but good on them.

I'm going to guess that very few people who are actually aware of what a Game Key Card is wants them.  Buying the game digitally outright where you can literally get it within minutes of buying it, can bring it travelling with you without bringing a bunch of cards, can swap games without having to open the card slot and possibly take the Switch 2 out of the dock, and not have a physical package that actually contains nothing eating up space in your house all seems vastly more convenient.  I imagine the "well I can resell it" crowd is pretty small.  I figure most people have bought these things without fully paying attention to what they're getting and might not even have noticed its not the real deal if the first time they loaded it they were connected to the internet.

After Nintendo said they wouldn't release Game Key Cards for their own published titles they backed out on that and then picked a Pokemon game to be their first title.  That is pretty shrewd.  Pokemon is an ideal title for this because its target audience is kids who don't know better and relatives of kids that probably have no idea that the Switch 2 games on the store shelf actually have multiple variations of Game Key Cards, full physical games and Switch 1 games that update to Switch 2 games.

The game itself is a follow up to Dragon Quest Builders, which is awesome, so I don't doubt for a second that Pokopia is as good as the reviews suggest.  If I had a Switch 2 I would probably get it... as a download from the eShop.