Ukraine cannot win without manpower from either the EU or the US. That's the reality on the ground. No amount of equipment/weapons (conventional) is going to change that.
According to the Austrian military, there’s currently about 800k Ukrainian soldiers up against 700k Russian soldiers.
Because a substantial number of Ukrainian soldiers need to be present across the Belorussian border and elsewhere in the country, the Russians have a meaningful manpower advantage on the frontlines.
Remember Ukraine doesn't need to take Moscow to win. Russia is burning resources hard to keep the initiative and achieve Putin's war goals. All Ukraine needs to do is continue to bleed the Russian army and wait until Russia has a hard economic crunch.