The FCC also decided that broadband is not a Title II service. One bad decision as a consequence of the other. If you put broadband under Title II where it belongs then you don't need VoIP to be there because anybody who can use VoIP (because they have broadband) is already paying into the USF.
The combination of net neutrality and PSTN sunset may lead to a "regulatory swap" where broadband is regulated and the phone network is not. The problem is always in the wires.
But the FCC already decided, in 2006, that VOIP is subject to USF contributions.