Thanks James and Ariel for the discussion, and no worry at all James, I’m very happy to see that I am not the only one wondering.
I indeed only have one tenant and mutli-tenancy would be overkill for me. Making all users full admin is out of the question as well.
While looking at other options, this actually lead me to another question. Imagine that userA created a notification (or probably anything else for that matter), then userA quits and their account is blocked. How can userB take over? For notifications at least, there is no way to change the owner. There might be ways to completely duplicate objects with a new owner but it sounds very brittle to me.