Waiting on God has never and can never be a waste of time. When God bids you to tarry it means he has sufficient grace for you. The more willing and patient you are for God to lead and direct you, the stronger you become and the further you go. Never be in a hurry simply because God has called you, when he calls you he says come wait on me.
but those who wait on Jehovah shall renew their strength; they shall mount up with wings as eagles; they shall run, and not be weary; they shall walk and not faint. (Isa 40:31)
When we move before he sends us we always grow weary, get late and eventually get it all wrong. You can never push God INTO something, only OUT OF something. He knows best when and how to act. If you are not patient enough to sit and wait on him, then you are not ready to move at his pace and be used of him. Dealing with God calls for patience since you move from the known to the unknown. You cannot understand God fully.
Trusting in God calls for patience, when you are patient he takes you with him, while with him there is no doubt you will get on the other side on time. Patience produces strength in the walk.