I dont know man...you would have to be really rich to not know at 13 that spending 2000 USD/€ secretly from your parents account could become an issue down the line. I get your overall point but...at some point, you just gotta the the responsibility and own up to your wrongdoings.
Kids in that age know the worth of money from their allowance, they know what consoles and smartphones etc. and how long you have to save for that shit if you wanna buy it on your own. 2k is too much to just brush it off as....boys gonna be boys.
I definitely think there should be some consequences for the child, but making him go out to work at 13 seems a bit much, in the UK you can work at 13 but only for a limited number of hours and there is no minimum wage, Say someone is feeling generous and offers £4 an hour, which is above minimum wage for a 16 year old, it'd take 500 hours to earn that. Now taking into account you can only work 5 hours on a Saturday and 2 on a Sunday that would take just over 70 weekends to pay off. They can work in the week a maximum of 2 hours per day, but ignore in this example. Also do you really want your kid out of the house in the current pandemic.
I think this probably comes down in part by the fact they were spending the money in little bits here and there and not getting caught, yeah 2k might sound like a lot to him but if he has not been caught when spending 10, 20, 30 etc. he might just be thinking great this isn't that big a deal.
The problem is though I think "boys will be boys" unless we teach them not to be.
I'm going to be honest and say that financially myself and my family do very well for ourselves, but I can't think of a situation where I wouldn't notice 2k being taken from our accounts even over a long period of time, that's what alerts, notifications and just manually checking are for.