When it comes to infrastructure, the frontrunner rapidly becomes the laggard. Someone building up their infrastructure from nothing can look at the forerunners and avoid their mistakes and include the latest technology while the forerunner has become dependent on the existing infrastructure so it must be maintained while the new system is built.
Consider a 'modern' road built in 1790. It would be wide enough for two carriages to pass, it would be paved in cobblestone, and would have amazing drainage that let the water flow off to the side rather than puddle up. Imagine you built out this road system for your entire city. Now Mr. McAdam comes along with his new paving system and your neighboring town that didn't get around to 'modernizing' their roads when you did now starts their own project. Their roads will be better in many respects. Do you tear up your old cobblestones and repave your roads? Or do you live with your system until it becomes a problem?
Fast forward 200 years. The amazing two lane carriageway is barely wide enough for a single modern car, the rights of way/easements have been established so houses are built up to the edge, and any upgrade to this road system is going to require not just regarding, but purchasing/condemning hundreds of properties. Compare that to a third world nation putting in their highway system. Lots of open space to utilize, no underground utilities to worry about rerouting or damaging, No overhead bridges built 60 years ago that require replacing (since they were only wide enough to span a 2 lane road not a 4 lane divided highway.
So something as simple as adding a new lane to an existing highway for 10 miles can end up costing more than putting in an entire 4 lane expressway for 50 miles if one was in a developed country and the latter was in an undeveloped country.
It's great to get new technology, but trailblazing is always more difficult than following the trailblazer.