I have an heavy problem on my Civicrm instance 5.36 on Wordpress 5.7.1 working in the backend, the time to open a dashobard is more the 20 seconds and every pages have similar time. By example: main empty dashboard take 22,9061s to open, but the query took only 0,3610s (the system cache 95,9% of hit: 6.246 hit, 269 miss). Civicrm is hosted and from cpanel there is no issue: CPU, Memory are used less than 30% Is there a way to analyze the problem?
Assuming you mean shared hosting, it's going to be difficult to analyze, mainly because you have no way of seeing the disk I/O or the database contention.
In my experience, this happens because WordPress because WordPress is bootstrapped with every CiviCRM API request, and some plugins (BuddyPress comes to mind, as does one of the multilingual plugins, I forget which) introduce a significant slowdown.
If you know how to set up a local test site, it would be good to get a baseline - is the problem server-bound, or site-bound? You can also use that to disable all your WP plugins and see how much difference that makes in timing. It's probably down to one or two plugins.