The Bering Strait, the Strait of Gibraltar, the Darian Gap, there’s probably about a dozen possible megaprojects that I could name that have been proposed but not built. The question is, should they be built? Is having the world connected worth the consequences of doing so?
Use boats, only legal stupidities stop people from offering ferry rides to the migrants.
If someone is gonna do some very expensive project, probably shitting over the indiginous people living there, why not rather stop all the reasons people end up crossing to it. At least change the part of considering migrants subhumans with no rights and everyone preying on them.
Doing such mega project because migrants is nonsensical.