Unless the end users need to edit the members of the list (e.g. add, delete), access does not need to be set. Adding roles to lists increases the memory usage, so only use when necessary. A user can edit data in a module without needing to have access to the list
Best Practice article:
Pre-Allocation in Lists (and Impacts to Model Performance
Questions on this topic? See 1.03-01 Only give write access to lists when needed in our Planual forum.