Fundamentally we had major problems with a disconnect with people never really being able to agree what HS2 was actually for. Nebulous "adding capacity" is all well and good, but isn't that helpful.
Personally I would have preferred the inverse S to the Y, even if we ended up with single ended stations and autoreverse.
All trains stop at all stations on the high speed line.
London, Birmingham, Manchester, Leeds and then on to Newcastle.
As it is, Sheffield demanded the eastern leg be broken to maintain its dominance over Rotherham, and after that there was no point building it at all.