Traditional design (up until today) deals with satisfying what people need. For when they’re out in the market, reaching their hand out to a shelf, looking for something to buy.
All of this is conditioned on a decision to have been made (I am going to buy a new car seat, sweater or potato peeler).
Design for agency could climb up that decision making tree, and help with the actual decision making process, independent if that decision turns money to your product (car seat, sweater and potato peeler), mostly because you’re already automating the production, distribution and sale of all of those.
Design that helps decision making is design for agency.
Design for agency helps people make decisions, without having an opinion on what the outcome of these decisions should be.