What McCarrick, and others, have done is undermine any credible authority that the Church has.
They undermine it with people who for whatever reason are hung up on this issue of misbehaving priests.
I would like to see the clergy clean up its act and I’m reasonably confident that they have and will continue to do so, because the bad consequences of not doing so have come home to roost in a huge way all over the world. Getting hit in the pocketbook gets clerics’ attention just like it gets corporate managers’ attention. As a believer in approved apparitions, Our Lady warned us this was coming, IMHO.
But there’s been sinful priests and bishops for centuries. They’re all through the Church history. When I was growing up, a lot of the clerics weren’t prizes either. I was fortunate that my parish somehow managed to avoid any accused minor sex abusers, but at least one priest was sent away for addiction and having an affair with a woman, and some of the neighboring parishes had priests committing other wrongs. I never thought of priests as particularly holier or more moral than other good people, and I don’t spend a lot of time dwelling on their authority. It’s not like I’m looking for misconduct by a priest to give me an excuse to go commit grave sins or to quit the church.
If someone else is looking for these excuses, then on top of the sinful priest, we have a person weak in their faith to begin with, and if it’s not McCarrick they blame, it will just be something else.
I know people complain a lot about “Me and Jesus” type thinking, saying that it encourages folks to skip Mass and make up their own morality, but if one has a strong relationship with Jesus and your eyes on him at all times, then your world doesn’t rock every time some clergy scandal or even clergy questionable activity (like Pachamama) crops up. You pray over it and you move on, with Jesus. Eyes on the prize.