Explain value of earning vs being given?

my ex is bribing our 17 yo with money, new truck, no rules, 4wheeler, new iphone and tge list goes on. I have tried to show my kids that if you wabt something you should earn it. I want my children to have morals and integrity but i cant make him understand that he should finish school and get a job and work for those things. Thats how responsabile adults get what they want. How do i explain by enabling him she is hurting him in the long run? I told him to remember that whoever gives you something also has the power to take it away or say if it was not for me you would not have that but he thinks im wrong and being mean. Advice on explaining or dealing with this situation?
Added (1). Sorry for poor punctuation and typos. I'm using an old phone with a tiny keyboard while my other is being serviced.

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