We can only leave the balance in the account if its not lost in gambling. Lol
Most often we don't have any money left to gamble at all. Many people including me gamble until all the amount is lost or we are exhausted for the day.
Hahaha, you are right

Not at all because I always save some amount that I prepare to be used for the next days so I can directly play without depositing more money

Now that's a rare trait. Most people gamble the money they deposit immediately but you have the resistance to control yourself and wait for the next day.
I generally deposit and play immediately and lose it all most often. The other times, I just save a few bucks and play some other day again.
If I get the free spins I use that first before making another deposit.
It also happens with me sometime like i deposit the money and instantly waste all of them by losing the bets placed and sometimes the deposited funds are used for whole week with some small bets scattered all over these days whether i win or lose.But most probably when you have deposited the funds your wish to place bets to enjoy and hope to win but it can turn out to be win or lose we need to accept it.