People very much have to work in Star Trek. If they don't, unsuspecting enemies like Q, the Romulans, or the Borg would eradicate the Federation's existence. They also have their own forms of scarcity. Replicators are somewhat common but Holodecks are not and members of the crew must schedule time to use them. Resource allocation is determined through the decisions of leaders in the beauratic hierarchy and the longer you watch, the more you see the ways in which the Federation falls short.