The goodbye you postpone can make a settled decision harder for everyone else to live around.

A decision made but not announced keeps other people in a holding pattern. They plan around a version of things that no longer exists, invest in arrangements you already know are ending, and later have to redo the work with less time. The delay usually comes from dread or kindness rather than calculation, which does not stop it landing as a cost on somebody else.

If you have decided something and are waiting for the right moment, consider that the moment mostly gets more expensive. Say it plainly and early, and give people the runway you would want.