Weapon production is something any country wants to build up domestically, otherwise the country wher3 the producer is situated can impose restrictions and political pressure - see the limits the US sets for use of US weapons or the German denial of Taurus deliveries, or the swiss refusal to give ammunition for air defense to ukraine
Counter point: the majority of the EU's defence material comes from abroad. EU pension funds where/are banned from investing in defence. The defence industry is tiny in the EU compared to the rest of the world.
And as a result, EU defense officials watch the US elections with dread, as they would be utterly helpless against a Russian incursion. Unfortunately, the time of the peace dividend we enjoyed is over, at least as long as authoritarian EU neighbours like Russia heavily invest in their military on a war footing
To be fair, that Swiss decision was completely reasonable. The systems they were scrapping were old, unmaintained and not produced anymore. It made no sense to invest time and resource to teach a lot of ukrainian air defenders in order to then launch a small limited amount of missiles and then scrap the system anyway.
I think by swiss ammo the parent comment refered to the 35mm ammo for the Gepard Air Defence System owned by the German Armed Forces that was produced by Rheinmetal (but in Switzerland) that had to remain in Germany.
AFAIK the Gepards are still in use in Ukraine, but Rheinmetal is now producing the ammo in Germany rather than using the former Oerlikon-Facilities in Switzerland.
