Steem power gets you a lot of followers and yes that helps your post to be seen by so many people because posts on steemit appears on feed and feed is basically from people you are following.
However that be it as it may, SP is not the most important factor in post visibility. Creating original and good contents helps. When you create good contents, people love it and then they reesteem it and gets more visibility from people on their following list. Again, sharing of links also helps in post visibility. You don't make a post as minnow and do not share the link hoping it would be seen by the world when you have a very small number of followers. Posts are made every seconds on steemit and in 5 minutes your post can be swallowed up.
Hence it is important to join communities and interact. Build a network for yourself. Let people know your niche and use the post promotion channel for these communities. It helps in post visibility.
Comment a lot on people's blog. Making reasonable comments in blogs of others will get people visiting your blog leading to post visibility. After all said, for your post to be visible, you have to do more than just having SP, you must work.
Quite exhausive an explanation! Thank you.
You are welcome