You can't withdraw your steem power at once. You must take minimum 3 months/13 weeks by down your power. If I have 1000 steem power I used to those powers themselves who creates quality content post but didn't get any upvotes. That will be good for me. I don't like to withdraw it because the price of steem and sbd is down now. When it will getting up I think that time would be the best time to withdraw.