Oh, and I just remembered that I once visited a local online casino that displayed deposit and withdrawal transaction history. Is this the feature they're referring to? I tried checking transactions for the past week (that's the maximum history I could check), and yes, I also saw that the deposit status was higher than the withdrawal status.
What you said is also true and makes sense: it's impossible for a casino to display everything in detail, especially the player's loss history, as that would defeat the casino's goal of maximizing profits.
I just checked one of the casinos I used in the past, bcgame and the stats I got there weren't really useful. I got the Total Wins, Total Bets, and Total Wagered. If you look at it, you might think that there are some useful stats, but in reality, there are not. The total wagered doesn't really tell you the total you have lost to them or the total you have deposited into your account. The total wins talk about casino games, and there are some where you would be awarded as a win, but the total gotten from it would be less than what you staked, especially those with multipliers lower than 1x.
Useful or not is depending on the gambler but if you think it is not that useful because total wager does not really tell the actual loss or deposit, means that you understand it wrongly since total wager has nothing to do with loss or deposit or even withdraw. If you want to know about your overall loss then you should take a look at your PnL statistic. Although it cant be 100% accurate but at least you can use it to manage your gambling funds.