That's a good idea but most of the trusted casinos out there provide really less returns like 1-3% a year as far as I have heard. It may be more but unfortunately it is still less than the return bitcoin provides you every year.
So I would recommend you to not invest in any caaino and let the bitcoin stay in your wallet.
1-3% in a year? where did you heard that? that return is when you deposited your money in bank. I've said if my investment increased 20% since i invested my money in a dice site (if you read my history post, you will know where i invested) on 6 months ago. The return could be more if someone lost a lot or it could decreased when someone won a lot.
Gambling sites offer good return compared to banks if you have a good amount of capital, you can double your money in a year and that is fact. When planning to invest in a gambling site, make sure you are into long term investment as the output cannot be felt in a short team. Casinos does not win on daily basis but they do win in the long run, think of that reality and you shall be convince and more confident with risky bigger.
you should never compare a gambling site investment or in general any kind of investment with what banks give you. because they are two completely different things.
in a bank you will 100% be sure that you can get a fixed amount of profit without any exception or it going wrong.
in any kind of investment you are not completely sure about the profit and amount of it and also there is always a big risk of losing money too.
i agree with you, investing in casinos can give different amount especially if casinos is not making much of money, but at least you still got profit with them but remember that in casinos you can not always take the profit sometimes the profit is not big as you can think and you need to spread your investment in other casino.