More often, I find that customers are working around the site permissions. For example, you want someone to have access to a specific folder, and instead of inviting them to the site, the customer adds the user/group directly to the folder permissions, then sends the link to the folder to the person they wanted to share it with.
There is nothing you can do with site permissions that cannot be done using "normal" folder permissions.
If you have people who are using site memberships AND structures in the non-site repository structure, it gets worse because people have to think about how to provide access.
So I see zero value in keeping this around.
However, I agree with Douglas' suggestion that if site folders could be created anywhere, that at least addresses the "number of sites" limitation. It doesn't address the competing approach to permissions, however.
Another way to think about it is to pretend we're in a post-Share world and you're explaining Alfresco to someone who's never used it. How will you explain the concept of a site? It would sound something like this...
"You see, a site is a folder like any other folder, but it has this extra folder called "documentLibrary" which doesn't do anything, it's just an added level of hierarchy that means nothing. Now, when it comes to permissions, we have Site Managers, Site Collaborators, and Site Consumers. For a reason no one can remember, you cannot use Site Coordinator even though you can add a user as a Coordinator to a non-site folder. What's the difference between a Site and a Folder you ask? Nothing, just the extra level of meaningless hierarchy and the inability to use Coordinator. I know, it doesn't make sense. This is left over from 2018. It was a really tough time in our nation and the world, but I don't need to tell you that!"
