Well, not all is lost. Some of that information is still out there. You just need to know the "backdoor" to them.
Here's a list of some of the links I miss from the previous version and their "backdoors."
Note: You need to be granted Site Collection Administration access in order to be able to use these "backdoors."
At the top level of your site, remove anything that comes after the site root URL, append _layouts/usage.aspx, and press <Enter> on your keyboard. SharePoint will display the page below.
Viewing All People Who Have Access to a Site
At the top level of the site, remove anything that comes after the site root URL and append the following:
If you are a Site Collection Administrator for the site, you should be able to see a list of all the people who have access to the site. I really like this page because it allows me to remove people who no longer work with us and I don't have to go fishing for them, trying to find where it is that they might have been granted access to the site. With this option, I can remove them from the site completely in one single step.