This is so true - Another for sure in life is that a lie, no matter how well crafted cannot live forever, but the truth will always remain 💯. You don't have to look far for the truth if you want to know it.
If both parents truly support shared parenting the effort towards making that happen would be equal. Bashing the other parent or fearing the kids might like it there too much is not an equal effort. Doing what is best for the child is an equal effort.