Politics makes or breaks projects. HS2 is only going ahead because there is cross-party agreement. Crossrail2 is seen in the north as a line in the sand as far as the bias towards London invstment is concerned
CR2 is likely to open in 15 years time, the reason it is up for discussion now is the account of lead time that it will take to get it going and then the length of time to build it.
It is all well and good saying that there needs to be more investment elsewhere, but what projects should that be?
Also, how will HS2 impact on those projects. CR2 is clearly something that improve when HS2 is built as it allows more people to get off a HS2 train and get around London. As such there's no rush that HS2 week make it redundant.
Conversely if you do something to gain you extra capacity into Manchester, that could be not needed after HS2 as that would also free up paths.
Without knowing specific projects for elsewhere how can it be seen if there is a real need (i.e. projects that would be of more benefit that CR2) or whether it is just a perceived need (i.e. "it's not fair, so we should try and balance things out" ).
To date much of the debate on here has been focused on the latter. Yes there could be a case for doing so politically and so some projects could be elevated advice where they may otherwise have sat, but even so to have a balanced debate there needs to be suitable projects put forward.