There's just not the capacity to do that. Nearly (probably all) railways into the centre at at 100-200% capacity in the morning and evening peaks. It isn't poss

There's just not the capacity to do that. Nearly (probably all) railways into the centre at at 100-200% capacity in the morning and evening peaks. It isn't possible to make the trains run any more frequently (incremental capacity improvement is possible at extreme expense, but nothing that would allow a step change in housing trends).