Europe is great at producing armaments as well - but there are a lot of useful armaments that are only produced in the US. If you had to choose either EU or US support, the US is the better option as they can give you things that the EU cannot even though the EU has more people than the US and a good economy.
The Patriot system is one the of best examples. EU doesn't really have anything in this space, but Ukraine needs more of it yesterday.
The European system often contain some American components. Perhaps the French a bit less so.
This has turned out to be a major problem, as the US has used their re-export restrictions on components to block very significant parts of planned European military aid to Ukraine.
I speculate that there will be (already is) some extremely heavy investments in military tech R&D to remove/reduce dependence on American components going forward. As a continent, we can't have our hands tied like this in future conflicts.
The Patriot system is one the of best examples. EU doesn't really have anything in this space, but Ukraine needs more of it yesterday.