It’s difficult to change the course of a heavy cruise ship, whereas a river kayak dances through rapids with the slightest touch of the paddle. Although a cruise ship has its place, the kayak is much more agile.
Agility requires flexibility and a lean process, stripped to its essentials. Anything more is wasteful. Eliminate it! The less you have to do, the less time your work will take, the less it will cost, and the more quickly you will deliver.
You can’t just cut out practices, though. What’s really necessary? How can you tell if something helps or hinders you? What actually gets good software to the people who need it? Answering these questions helps you eliminate waste from your process and increase your agility.