I think the US defence industry really is going to be hurting for awhile for the trustworthiness reason alone. The Patriot was under-promised and over-delivered as shown in Ukraine (the Americans seemed happy to let people think that its teething problems in the first Gulf war were still a factor), but even if you buy it the supply is constrained to a country with what we can now describe at best a "mercurial" political system.

Russia's exports have more cratered because they're focusing on domestic demand, but they still have a market for developing countries fighting amungst themselves that the west won't supply. The one exception is India, which will likely pivot to more western kit as they have border issues with China.

Korea already had a domestic industry for various strategic reasons with North Korea being next door (if a global war became hot, they could be cut off from artillery ammunition sources, so it makes sense for them to make sure they can manufacture their own, even if its more expensive), so they're in a position to capitalize. Canada's reasons to do the same (massive arctic defence) doesn't have much of an export market, though we are teaming up with the Scandinavian countries for icebreakers.