Hard to say. People were saying 10 years ago that iron condor will be dead once too many people start using it.
The liquidity issue in our case is not related to a strategy. If we traded only stocks like SPY or AAPL, we could trade tens of thousands of contracts. But buying 1,000 contracts on less liquid stocks could be tricky. The market simply doesn't have that kind of liquidity.
As for the strategies themselves - as long as traders have different opinions and different views, the strategies will continue working. As you correctly mentioned, it's all about management.
But nobody should try and trade those strategies in a fund. Please trust us on this.