The headline is actually misleading. It's just that neither Egypt nor Sudan can claim it without giving up the claim to Hala'ib Triangle.
And Bir Tawil is just a worthless desert, but Hala'ib Triangle is mostly fertile land with a sizeable shoreline, so why would anyone pick the worthless desert over it instead?
> without giving up the claim to Hala'ib Triangle.
Well, strictly speaking, either country could decide to claim both areas, it's just they believe that by doing so they would be lessening their chances of their claim over the preferred area succeeding. So it might be more accurate to say "without weakening their claim" instead.
"Mostly fertile land"?? I don't think either are worthless (I love deserts for their own sake), but to describe that triangle as fertile is ... not very close to accurate!
And Bir Tawil is just a worthless desert, but Hala'ib Triangle is mostly fertile land with a sizeable shoreline, so why would anyone pick the worthless desert over it instead?