the recreational pilots licence is a reincarnation of the old restricted private pilots licence.
it is a simple historical fact that most students (back in the 70's) ran out of money mid way through their training. ...funny same as today.
the restricted pilots licence was issued after the basic aircraft handling had been mastered but before the cross country navigation training had been undertaken.
a Restricted Private Pilot licence + navigation training = the unrestricted private pilots licence.
the words unrestricted and restricted referred to the presence or absence of navigation skills.
....i know. the obvious is a lot harder these days.