The Burscough Curves may seem "unglamorous" but it's this kind of focused, specific investment which opens up so much more possibility and should be the kind of infrastructure project which local authorities had the power to fund.
Preston to Southport by bus (the trustworthy workhouse X2) is a long, twisty-turny route through semi-rural suburbia, and is an unequal hybrid of express coach and hail-and-ride stopper. The Curves would offer an alternative. Not a replacement (for some of the communities on the bus route would have nothing were it taken away), just an alternative additional extra. The A49 over the River Douglas at Tarleton can get chocka, at the best of times. One smashed wall from one unfortunate accident and the entire route is closed: the Curves would come into their own.
That said, for the interest of balance, just relaying the Curves and getting Northern to run trains up and down would not be enough. The line into Preston would almost certainly need re-jigging, so services getting onto the WCML could do so without standing at Farington with the engine ticking over for too long. The line into Burscough and Ormskirk would need re-jigging, as MerseyRail would suddenly have a semi-kind-of-almost competitor into their territory. The line into Wigan would need re-jigging, not least because Southport <--> Wigan <--> Manchester services would need a few minutes added into the timetables with knock-on effects, however minor.
Lancashire County Council has (repeatedly) rejected the Curves as financially viable to re-open. This matters, because the argument in favour has to have a positive BCR. One tangentially related issue will be the Skelmersdale railway station scheme, if that ever gets built, because West Lancashire could then have a better financial case for linking Southport <--> Burscough <--> Ormskirk <--> Wigan.