The amount of people investing will not make it unprofitable as it doesn't affect the odds (house-edge). What it does is make your cut of the bankroll smaller which means a small win/loss won't affect as much. Basically the risk will be divided. Therefore there won't be as big fluctuations.
What you said it correct. But if bankroll increases then investor profit will go down, and at the same time, their risk of losing more money also will go down. House edge will be same but profit is shared between all investors so if more number investors and bigger bankroll than investor profit also will go down.
This will hold true only if the number of gamblers remains the same, or, more correctly, if the amount of money they gamble away doesn't change. Therefore, it is possible that profits may remain the same even if the bankroll increases due to more people gambling. Regarding risks, they may also remain basically at the same level because the casino might increase the maximum bet amount along with the increase in the bankroll, which would be perfectly warranted.
It s also possible less people gamble and bankroll increases and then you get even less money. Not to mention if some gambles scores big time win. In that case, it s an issue.
That actually wouldn't be an issue, at least, not in terms of percentages. I mean ROI much discussed recently here and which is typically measured in percentages. If the house increases the max bet amount that means a big whale would be able to grab more coins from the bankroll if lucky. Or lose if he is not. So, in reality, there is no such issue that you are talking about.
Percentages would remain the same.
