What exactly is the benefit of an intertie if it’s always running at max capacity?

How would it “make infrastructure more reliable against extreme weather”?

It can’t be used in the event of a local station going down, because it was already running at max capacity anyways. So yes, it stays up while the local generator goes down, but it’s not enough to keep the grid up by itself.

It is well known that BC buys cheap power from AB, but I didn’t know the extent of the restrictions to sell power back to them.

I guess competition is scary and in their mind hampers further investment? And the bout of banning wind/solar farms still defies any explanation.