When buyers use PP,  the transaction is direcly between  PP and Ebay.   Since Managed Payments  ebay pays the  2.5%  PP fee direct to PP,  however   Ebay sellers fees were increased by 2.5% to cover the fee being paid to paypal.

Note  The 2.5% increase to ebays seller fee,  not only goes to covering the PP fee, it also covers fees to all other ebay payment methods, whether the the actual fee is higher than 2.5% or not.