For nearly all attempts to earn on the other platforms, most will fail to earn anything, yet all will pay a cost.
Once Hive's use case as a way to trade against BTC to gain more BTC goes away, that will be the case for Hive, too. The failure of BTC would be a complete disaster for Hive, unless Hive already had a very large user base made up by consumers who do not mind paying a little bit for Hive Power just to be able to participate.