Plenty of european countries have given both stockpiles and modern weapons.
As an example sweden has given Strv-122, CV90, Archer, Saab 340 AEW&C and has offered Gripen fighter jet (but Gripen has been blocked by US/France). All of those are up to date weaponry, and besides that much from older stockpiles has been given.
That's just one example from one small country with less people than one city in the US.
This has very long term repercussions for the US. No-one is making the mistake of using a US jet engine in their design again and getting export controls because of that. Already plans are evaluated for switching to an upgraded Volvo RM12 or something from Rolls-Royce.
The same scenes must be playing out in various industries across Europe and the rest of the world. Such wheels turn very slowly, but they now turn away from the US defense industry.
Certainly a world where NATO countries spend <2% of their budget on defence but the shiny new weaponry all comes from US contractors doesn't seem obviously more helpful than one where they're targeting 3% spend but making a point of building domestic industries or buying from pan-European projects.
Plenty of NATO members already build and buy from non-US sources. France basically made it a principle because of their historic fence-sitting NATO policy, Sweden mostly builds its own (but licenses parts from US/UK like fighter engines), other countries are buying artillery or tanks from south korea, etc. The US itself buys anti-tank weapons and riverine patrol boats from sweden, dutch rifles, german handguns and much more.
"but the shiny new weaponry all comes from US contractors" is not true.
It is true that the US has spent far more on it's military and made it far more global than any other country. It is also true that the US acted as a guarantor for west Europes security for most of the last 70 years and that should not be understated. That era seems to have come to an end.
I'm not suggesting the US has ever been literally the only NATO member supplying arms. I'm suggesting US companies have gone from the top of the list for a lot of procurement contracts to the bottom.
As an example sweden has given Strv-122, CV90, Archer, Saab 340 AEW&C and has offered Gripen fighter jet (but Gripen has been blocked by US/France). All of those are up to date weaponry, and besides that much from older stockpiles has been given.
That's just one example from one small country with less people than one city in the US.