When you see a declining trend….
When you see a declining trend, the first thing to establish is whether it is a market behavior or a company specific behavior. The picture below showed a declining trend in the number of impressions of a website. The first reaction we have is drop in traffic for the website and panic.
What I would do is to download the data for the website from Google Search Engine Console and identify whether there is a drop in the position. If the position is maintaining or better than before, then the impression drop is market changes. If the position has dropped, then the drop in impression is caused by the webpages which we have much better control. This is how we could react to the drop in impression. Without data, this is not possible to establish.