How big are the unstaffed 50% though? A branch line station with a few trains a day, much simpler ticketing arrangements, and no menacing signs telling people to buy a ticket (because its not a penalty fare area and can't be since it doesn't have adequate facilities) is quite a different proposition to taking ticket offices away from the main line stations.
But if we're making comparisons, I can think of towns and cities where most bus stops are obviously unstaffed, but the major bus interchange usually has a bus company office nearby who can sell the more complicated/expensive tickets and advise on what buses to take, including that of other companies if they are particularly helpful.
Big in what sense ? Number of platforms ? Number of trains ? Number of users ?
Not all "unstaffed" stations are quiet rural backwaters - take Isleworth for example in South West London - that's unstaffed, yet pre-Covid had over 1.3 m users a year.
