The wrinkle is the process that can remove defilement is the same one that creates it, and we've been doing it for so long that it's almost completely transparent.
Technique and understanding can be just as much of obstacles as anything else.
For some who may get too much in their own heads and theories, something like just sitting can be a way to see these habits for what they are.
My own habits of self are strongest around thoughts and mind as "mine" versus the body or emotions or other things.
Just sitting has been helpful in loosening this grip.
I wouldn't presume to discard an entire meditation practice, because it likely comes from a place of insufficient experience and incomplete ideas.
Not everything's for everybody!
I find the "just sitting" styles of practice I've learned from the local Soto center to be invaluable.
It's not the entirety of what I do, though