This piece of conventional wisdom is almost never true. That ‘they were ready’ is very often the a posterity rationalization.
Most revolutions don’t start when people are ready. In fact they start when people see others doing something and they feel they have to be … errr… ready. Readiness is very often a state that people feel when one has already started to move.
Don’t wait until the leadership team is ready. The leadership team may never be ready, or only ready when they see other below are moving.
Don’t wait until your team is ready. Start moving, they will get ready.
Don’t wait until you feel ready. If you want to be ready, move.
There is no state of readiness in your mind. There is fear or excitement or being stuck that we translate in to the binary ready/non ready
‘I would do X, but they are not ready’ may just hide our incompetence to get people moving. Get them moving, they will be ready, and you will see how much power you had in that supposed readiness.