Reason the Greek practice worked was you could tell everyone. It wasn't a thing like it is now. Same thing in pre-contact Hawaii and various other cultures where old and young could pursue romance. In a culture where that's ok or even normal it works,
You appear to be defending pederasty.
As practised in ancient times sure. Those cultures are the ones we celebrate today for giving the world democracy, philosophy, and the sciences. Be hypocritical to acknowledge those contributions but ignore the other stuff. Fact that modern depictions of ancient Greece skip over the homosexuality, bisexuality, and pederasty (every series about Hercules glossed over the fact that in actual mythology he was a notorious bisexual, and the Brad Pitt "Achilles" in "Troy" made his lover into his cousin, etc.) is why people have a screwed up impression of this kind of thing.
I don't approve of it today. Culture's completely different so what worked in ancient times wouldn't work now when most countries regard the onset of adulthood at 18. And when people try to justify adult-minor sexual relationships by pointing to the past they're glossing over the fact that people didn't live as long, and the chance of your dying in a some violent conflict was high so of course you were sexual earlier.
If in acknowledging reality I seem to be defending reality that's because I am. It's part of those cultures. Can't change the past by agreeing or disagreeing with it. But nothing's served ignoring or denying it.