What I wish were obsolete is Up and Down. To everyone North of Watford - OK Milton Keynes - we go up North and down South. And how you allocate Up and Down to routes which don't serve London (they do exist!) .....
Have to disagree with you here. The Up and Down system is long-established, and readily understood by the vast majority of operational railway staff. If it ain't broke ...
The fact that it seems strange to the general public or some enthusiasts is neither here nor there. It's technical terminology to facilitate safe railway operation which is the main thing.
And Up and Down routes which don't serve London are allocated on the basis of HQ being Up (so on MR routes Derby is Up - hence Birmingham to Derby is Up; on L&Y routes Manchester Victoria is Up - hence Wigan to Kirkby is Down).
What alternative would you suggest?