A known thing is that the longer you have your WordPress site the more plugins it has installed. From time to time I make some effort to review the list of plugins installed on my WordPress sites and delete the ones I do not need very much. This sounds easier then it is, as every time I do it, all my installed plugins occur very important. Therefore the amount of plugins grows over time. One of the drawbacks of such situation is that many plugins add metaboxes to your post edit screen. As a result of such situation, the post edit screen gets really messy, making it hard to use. This also usually applies to every custom post type edit screen.
There are 2 ways to solve this issue