In a high tariff environment where the Canadian economy needs to export even more to make up for the shortfall in exports to the USA, a 70 cent dollar works much better than a 80 cent dollar.
Put another way, tariffs make it more expensive for Americans to import Canadian goods, but a 70 cent Canadian dollar makes it cheaper.
80 cent dollar just makes whatever tariffs bite more, because instead of something that costs 70 dollars, plus tariffs, will cost 80 dollars, plus tariffs.
I'm not saying that article is wrong, but I will say 2021 did not have the Americans tariffing everything and us needing to shift our trade around internationally in 2025 on their radar.