I can kind of see what you are saying. The obvious model of Splinterlands is the TCG model. Open packs, then secondary market.

But I would disagree some too. This is not all there is to it. That does exist. But you also are rewarded for playing the game. Winning ranked matches. Daily quests. Seasonal rankings. All earn you some kind of monetary value.

I'm pretty new to the game so I don't know the extent of it but just looking at the amount of DEC top players get for winning a ranked game, if one were to be pretty hardcore about the game, you could probably earn a small wage just playing at that level. Like $50-100 a day. And that's not even including the reward pools for the other stuff or using the secondary market for selling/renting cards, just purely what you earn from winning games.

If that's not play 2 earn, not sure what could ever be considered play 2 earn. Granted I think there can be and will be better games that implement similar or better play 2 earn mechanics. But I do think what Splinterlands does is both a TCG model AND play 2 earn.