The biggest advantage of gambling with Bitcoin is that it is private and tax free. The government cannot benefit from your money. However, the biggest disadvantage is; its value is constantly changing. You must calculate the amount you use according to at least 3% variability. Otherwise, you may lose a little while trying to make a profit.
While I agree that the volatility can be a pain when you gamble as you could have earned a lot of bitcoin during a session only to find out that you lost in terms of fiat when the market crashed, this is something in which we had years to learn how to handle.
Personally when that happens I think about it in the same way I think about my bitcoin investment, maybe its fiat value is down but in the future it will go up, besides we are gambling with satoshis and not with fiat so as long as I got more bitcoin in my wallet I think of it as a win.
I don't mind if the bitcoin dumps as long as i am holding my winnings in bitcoin.
The main problem in gambling is that you have a lot of risk of losing your money. I have seen people invest their savings and hard earned money in bitcoins and later they lost all the money in gambling.
So its not mainly about your portfolio value in terms of dollars but also the risk involved in gambling is a big con for bitcoin gambling.
I feel, when bitcoin is used for gambling then yes, trading and gambling dont differ much when it comes to earnings. As bitcoin / crypto market is volatile, as long as you hold the coin earned from gambling and trading, the benefits will be more. Yes, there will be pain when Bitcoin earned in bull market winning in gambling and later the value goes down at bearish market.