Isolating the feature of your pages that is causing friction for audience engagement and fixing it is typically an iterative process. Change one thing at a time and test it out. Sometimes you don’t have time to do that. You might need to change a bunch of stuff at once and test the whole collection. But if you have time, it’s nice to identify the likely causes of engagement friction and fix them iteratively, testing in between. How do you do this? Running two versions of your pages and comparing how they do over the course of a month or so is the best way. This is called an A/B test: You serve an A version and a B version randomly to your users and test out how they click.
A month is an arbitrary time frame. It really depends on how much traffic you get. You need enough traffic to your pages for the results to be statistically significant. Google is continuously running A/B tests and it can do a new test every day in some cases because it gets so much traffic. Your mileage may vary.