Grandparent's eldest son leeching off of them

My parents and their brother's family live with grandparents and my parents are the only caregiver to my grandparents
Non-US
We live as a joint family but with my grandparents living groundfloor and their 2 son's families living in 1st floor.Their elder son(my uncle) and his wife have done nothing to support my grandparents and have been leeching off of them while my parents provide all the care(food mostly since we they have a maid)

It has been about 10 years that we are the only one's working for them.I love my grandparents but when I see my uncle basically abusing them and us in the process I feel angry.I asked my grandparents that if they give us everything equally then why do they not take work equally from the 2 families.My grandpa always lies and says that I do not talk to them while I have seen that whenever uncle and his wife need help they always help them.I am not against it but if u want all the work to be done by one brother while the other one just leeches off then it starts to feel kinda abusive,atleast to me.My aunt even said that my grandparents do not equally love their kids because I am the only son while she herself offs them and do not let her kids even approach my grandparents.

Last night I said to my grandparents that if u are giving us equally then why not u take equally as well and my aunt started fighting with me(19M)saying that I want to take them out of their house and that they have right to live here.(only my grandparents,mother,sister and 1 of their little daughter was at home besides my aunt atm).She then said I will police complain about u and that she will write a note about me after dying.I angrily told her to write it then and then she kept on pointing fingers and saying that she is not talking to me.She also said that I am an adult now and that I will go to jail for this.one person from the neighbour came into our house during the fight and told my graandpa to discuss it with himself and his 2 sons about dividing things equally(My grandma has mild dementia so she always forget what happened after the fight).My grandpa said yes to him and later when I asked him he said that he discussed it and that i wont be disturbed.When I asked my parents about it they said that he was lying and that never happened(which is true since I have not seen them discuss anything after the fight).I angrily went and told my grandpa that now we too will not provide care for them and leech off of them like their eldest son.They did not say a thing(since they need someone to care for them) but refuses to do things equally.Now Im feeling very bad for saying it to them cuz they love me but failed to take a necessary step.I will be joining college next year so I will be out but this has been mentally scarring me.SO PLS ANY HELP.