so basically i deleted a wordpress user, and with that user, the settings, media and many pages were deleted. is there a way to restore only that user, because he has been inactive for about a year, and the last backup is about one year ago.
I just did a test on Wordpress 5.4.2. I made a new user, and then made a post and a page from that user, then deleted the user and chose not to reassign content to another user.
I looked in the database and found that the data in wp_users for the user was completely deleted, but in wp_posts the content created by that user was still there but set to trashed.
So, you may find that you can recover the posts/pages from the trash, however if they've been deleted from the trash they might be gone permanently.
You can always recover data from backups manually, however it would be quite a manual process to find the data from the backup and re-inserting it into the database manually, or re-entering it through the WP dashboard.
For more help see if you have a database backup that you can look at in a text editor and search for your wp_posts table to see if you can find where that information is, and paste an example of it here.