So what exactly is a 'Platonic' friend?
A philosophical or rhetorical "friend" who is not in reality a friend
Matt. 22:12. And he saith unto him, Friend, how camest thou in hither not having a wedding garment? And he was speechless.
That sort of "friend" or maybe a "frenemy" or a backstabber or traitor.
Without any particular regard to morality or intimacy — not the sort of person you want to be hanging out with — however well-placed in society or well-respected in the community.