Here is an example of the difficulty of building a major infrastructure improvement, in this case, a rail line from China to Thailand and thence to Singapore. Who’s got the money?
The answer is no one; and so they can’t agree on terms that advantage all of them fairly. One interesting factor is land use rights. Thailand and Laos will not give the Chinese land development rights on each side of the rail line. Those were expected to help the Chinese pay for the route. I think those countries are right to retain their sovereignty over the land.