More than 500 BTC net have been divested since the change came into effect, though admittedly that's less than I had expected. Whether that's because investors are "playing chicken" with each other or their demanded rate of return is lower than I assumed is hard to say. In any case, I have no doubt that the bankroll will eventually reach a saner size as commission rate continues to increase to match Bitcoin's price.
Regarding alternatives: I've seen some interest-bearing accounts for Bitcoin, but none that offer more than 3% per year. IMO that's way too low to justify the risks, though, especially the significant counterparty risk.
I know this is bitcoin investment here, but alternative doesn't have to be bitcoin neither. Even ETH regular staking is around 6% right now, and like jungian said there are few that gives similar for bitcoin as well. And if you go towards BNB, there are places that give 100%+ in the defi world, so there are many alternatives. The point here is that this place is more trustworthy, not because it is profitable. Sure this place made people a lot of money but there has been places in the defi world where people turned 16k into 1.6 million dollars, and there were places where everyone got scammed.
Bustabit is not and never was the most profitable place, we never came in here for the money, we came in here because we knew that even though it is a tiny profit, at least it is guaranteed, and for the long term I made a good profit and that is why I am not leaving, because I know that I will profit one way or another, there are many other places that can 10x my profit if I get in at the right time and if I am lucky, but I won't take that risk.