Sadly, it would mean a catastrophe for Ukraine if US stops weapons delivery. We already saw this scenario which resulted in fall of Avdiivka and other huge problems for Ukraine. Heck, EU isn’t even capable of producing enough shells plus there is a lot of weapons that have US parts and would be denied to use, such as Storm Shadow and similar.
Are you aware that huge crimes against humanity, genocide, wars, heck even dictators and nice things like that are produced by … democracies?