Ability and willingness are separate, but kind of linked in some ways.
You can want to fly, but be unable. You can eat a turd, but be unwilling.
Willingness doesn’t cancel ability, but willingness can affect whether the ability is exercised.
Now, philosophically there is the idea that the will or your desires is tied to what you do. You won’t do what you don’t want to do.
Even in a situation where you’re coerced to do something against your will, like give a robber your wallet at gunpoint, you actually were willing to give your wallet, because the alternative to giving the robber your wallet was to be shot.
All men are free to do anything they please. Some people’s pleasure seeking falls short of what they really want to do because of the consequences.
I can roller skate. In my youth I was quite a good dancer on those roller skates. But, with motherhood, I stopped going to the roller rinks. I only went a few times when my sons thought it would be funny to get old “Mom” on roller skates, then I skated circles around them. Now, my old bones are brittle and easily broken. I know I could balance and skate, but I am unwilling to put my bones at such risk. So, roller skating is only a memory in my life. I guess it is the same as never having roller skated, at all. Except, I have the memories.
I have the ability to fly, but that ability hinges on the willingness to purchase a ticket on either a commercial flight or a charter flight. Then there are choices to be made whether to use Delta or United, Southwest or Sun West…and I have the ability to chose, but at the moment, I don’t have the willingness to fork over my money to purchase the ticket. There is a third possibility that could be explored and maybe should go along with Ability vs. Willingness, and that is Desire: which at the moment I don’t have…I don’t have the desire to go anywhere on a commercial or charter flight. I’m just going to exercise the ability and willingness to stay where I am.