Because the thread asks What is player agency to you?Why? If you're happy with the amount of agency you're getting in any given game, what does it matter how much you actually get?
Because it is interesting to talk about the way in which different techniques in RPGing conduce to different degrees of agency for different participants.
Because I am interested in how to use different techniques in my own RPGing.
I didn't realise this was a forbidden topic!