Splinterlands is not self sustained, beside dhf founds, basically every development is being paid by the Dao, lands, validates, etc... They would be dead already without Dao...
Risingstar active players keeps dropping weekly... So I don't really know what games are really sustainable, let's see holozing...

The problem with hive monetizing is that you get votes only if you know the right persons, I see trash content getting big votes just because friend of someone or autovotes, and good content getting little to nothing