Do you think that parents and kids can't tell the poorer kids from the richer ones by any other means but whether they get FSMs?
Cos inequality is so bad it's not exactly difficult to work it out other ways.
Not claiming cuts your nose off to spite your face and makes it harder for schools in general.
Just take it. Fwiw I don't care who gets it. I get judged as if I do. Misconceptions work both ways. Nor do you know which better off parents got fsm meals as child or have claimed them in the past for their own kids.