In my personal view, there were some crazy suggestions that (thank goodness) failed to go through as Liverpool Exchange to Southport and some which happened and are so sorely missed these days like Oxford to Cambridge.
The Southport proposal resulted in the chopping of a well used and popular electric extension of the Merseyrail system to Crossens. I knew locals in that town who couldn't believe that their service would be just ripped away.
The very popular South Wales resort of Porthcawl lost its railway because of low passenger receipts from that town. The truth being that all of the traffic supporting the railway was coming into the town.