In Germany a 17yo cannot drive, CAN drink and can have (I'm old and it doesn't apply to me, so this might be only somewhat accurate) sex with other people (but cannot be a prostitute), might marry (needs parents approval I believe). Age of consent is 14 (but .. not for sex with adults as far as I'm aware).
I know that German law has nothing to do with this. But please stop and reflect for a second: The US allows 17yo to steer 2+ tons of steel at high velocities, Germany (as the one example I'm familiar with) lets them have consensual sex or drink beer. The same way you say 'How can they agree to sex' one might ask 'How can they be responsible enough to drive'.
It's cultural, not absolute. I understand the outrage, I am in no way defending Epstein, Stallman or anyone here - but please don't present your moral position/your upbringing as absolute truth. See it as something that you were raised to believe and that A LOT of people disagree with on this globe.
(It's obviously not helping the fact that the girls got paid, it's a completely disgusting, sad and shameful story with no recourse - but don't claim 17yo can't have sex with someone older, ... just because)