Combine Multiple Roles into one single attachable entity, which would be attached to a User account, to provide total cumulative permissions of the Permission Set.
A single user can be, and often is, assigned to multiple roles. Users inherit the most-permissive setting of all roles that are assigned to them.
You could build all permissions into a single role. For low-complexity environments, this works well.
You could build discreet roles for sets of permissions, and assign multiple roles to a user account.
This approach does introduce complexity; but it allows for easy scalability and identification of total permissions, and compartmentalizes changes to the roles.
Example/Use case(s): See visual examples below