Nah you just said something that wasn’t correct.
Good Lucio’s were able to gain speed since there was little to no momentum loss, now the momentum is lost so quickly you start losing it before you even hit your next wall. Your overall speed has gone down hugely unless you’re in a corridor like on Numbani point A where you can continuously wallride - barely losing any speed.
Huge nerf for his speed and huge nerf to his skill ceiling since all forward momentum (up until a certain speed) remained forward - meaning you just have to hold W and look in the direction you want to go. Your character will turn that direction and have very little impact on speed (apart from the before mentioned momentum changes).
Mercy, on the other hand, was very little skill (mass rez) and turned into a tiny bit more skill required (valkyrie, through all it’s versions). You simply cannot compare the two.