You keep missing the point.

That billion $s is not promised just for Noront's benefit. It is for the whole Ring and some surrounding communities.

Example, E/W road is also for cheaper delivery of goods and services all year to communities beside it. And this road is to cost a fraction of the billion.

Another fraction for electrical power from grid. Remaining $s will serve for only a fraction of cost of railway. That is why Ontario wants federal government to contribute and are probably hoping for support from private investors, per Mushkegowuk.