Whatever one thinks of the HST2 project (and it has not been too popular scything its way through rural Warwickshire) any benefits would not be secured by terminating at Birmingham (or at Old Oak Common at the other end).
The Institution of Civil Engineers has produced an interesting report on the whole mess: https://www.ice.org.uk/news-insight/news-and-blogs/ice-blogs/the-infrastructure-blog/lessons-from-the-cancellation-of-hs2s-northern-leg
It's interesting because it does pay sufficient attention to the politics, in particular the turnover of senior ministers (nine secretaries of state for transport). And, perhaps surprisingly for a report from an engineering organisation, it admits that it was over engineered.
