To address the cache hit rate, can you follow the steps in this guide and enable the option to Override Cache Control Headers?
https://support.ezoic.com/kb/article/how-to-improve-my-cache-hit-rate
You'll also want to review your content strategy to keep users more engage on your site, including longer content potentially. The average engaged time per visit is just around 15 seconds, which is relatively short. The more time users spend on your site, the more ads they will see to boost your overall ad revenue.