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.
I have had that experience before. After the deposit arrived in my account and I directly use it until the money was a drain.
But then, after use that method, I consider splitting the deposit money for some days and am trying to hold myself not to use all of the money because I do not see that can give me the win.
It is hard for the first time, especially once we got fun from gambling, making us forget to manage the money.
If you can do that, you do not get the experience of losing all of the money. You will still see some money in your account, but you still hold yourself from playing for more rounds.
Getting free spins after depositing will be a bonus so we do not have to spend the money before the free spins are gone.