Impressions doesn't mean you're in the top position to get a click. It just means your link was generated in search results and supposedly your link was visible to the user. You can be several pages back and get an impression but zero chance of a click. If you're on page one, you're pretty much always getting an impression although most clicks land with ads or the first three organic results.
IMO if you're not on page one for a keyword you care about, your goal is to get on page one. Impressions don't matter past page one for most searches. If you're on page one, you have two goals. One, to move up to the top. Two, to make your information in the serp as attractive as possible to the user. That's when I would start to care about tweaking the description, title and image so people don't want to scroll past my url. If you're on page two or three, chances are good nobody will see or care about whether you have the most enticing description.