The obvious, that it was "too expensive" like Israel's Lavi program: https://www.thecanadianencyclopedia.ca/en/article/avro-iarro...

But there was the idea that the CIA didn't trust Canada to not sell it to an enemy of the USA. If the Arrow had existed under P. Trudeau, that was a justified fear.

..and then eventually, having no aerospace program, Canada goes on to buy F18s from America.

I think the Arrow was an economic threat couched in strategic language. The arrow was kick-ass long before 14s, 15s, 16s,18s entered the science. And yes, they have different mission scenarios, but like Avro wouldn't have owned that space. #disgruntledCanadian