But is it possible to hide or block editors from even being able to access Projects?
If I accidentally published a project is there a way to undo, or is it a case of going to each page and reverting back?
Also curious to understand why Projects feature sits at the bottom of episerver? Seems more logical to me that it would be a gadget or a tab at the top.
No, there is no way to restrict access to the projects feature for individual users. It is either on or off for all editors on the site.
Actually, there is no way to "publish a project" - the project is just a container for individual, but related, items. From the project, you can select and publish multiple items in one go, but there is no way to "unpublish" items from the project. If you publish multiple items from the project, you would have to go into each topic and revert it. But have a look at David Knipe's clever GitHub project which automatically creates a backup project containing the original versions when you create a project. You can then use the backup project to republish the original versions: https://www.david-tec.com/2020/04/unpublish-content-changed-when-using-episerver-projects/
I can't say for sure why it was designed the way it was, but gadgets can usually be added and removed by the users themselves. The projects feature is enabled for the entire site by default and can only be disabled for the entire site as well. I think the idea was to create easy access to the projects for editors while at the same time not being in the way during work.
I have the Projects feature installed on my episerver. I found this enhancement is available to block editors from touching admin projects:
https://world.episerver.com/add-ons/episerver-labs/#ProjectEnhancements