It's not in GNE's commercial interest to create more direct services, as cyncial as this sounds.

It makes more sense for them to make you change at Gateshead, Heworth, Washington, Eldon Square or Chester Le Street so you'll buy your red or purple zone ticket

They'd rather you travelled on the 21 from say, Birtley to Gateshead and then changed to an X66 than put on a full direct service all day. This means they can sell you a day ticket and they hope you'll take out a key card and increase your loyalty

Where there is demand to make an obvious profit (say the limited X22 Chester-Metrocentre or even the X9/X10) they'll run the route of course.

Re- route discussion.

777 was Sunderland - Metrocentre, this replaced the 183 which was Washington-Birtley-Low Fell-Shipcote-Bensham-Metrocentre, then it was axed and replaced with the 77 became Sunderland-Newcastle via Washington area, Barley Mow, Birtley, Wrekenton, QE, Gateshead-Newcastle with later journeys and Sundays ending at Gateshead.

Other 700 series were the 735 from Houghton le Spring to Newcastle via Chester, Birtley, Low Fell which became part of the 21 as the 21A then disappeared. and the 733 became the 28A.