The US economy is over 10 times larger than the UK economy. In 2023 US GDP was $27.36 trillion, whereas UK GDP was £2.274 trillion that year (the latter's economy is also 5% smaller due to Brexit). Japan's GDP in 2023 was $4.2106 trillion (approaching double that of the UK). You can hardly expect an economy as small as that of the UK to match the USA's contribution. The US dollar is also the International Reserve Currency which means you can basically print money without domestic inflation.
Also, most of the US contribution is not current taxpayers' money, it is mainly money already spent on the USA's huge defense budget going back 20 years (for weapons and ammunition), just 3-5% of last year's budget. That money would never reach US taxpayers even if it was not given to the Ukraine. They don't give them much actual cash, when they say $40 billion to Ukraine, what they mean is the original value of hardware, shells, missiles, bullets etc, very little of it is cash and that's mostly only for humanitarian aid.
I think the $300 billion in Russian assets frozen in Europe, the USA and Japan, should be used to support Ukraine’s war effort. (More money than that would be due to Ukraine as war reparations from Russia if there was any chance of making Russia pay out in the future.) It could allow the Ukrainians to hold their positions and escalate their attacks to the point where the Russians would be more amenable to a peace deal with fair terms for Ukraine.
Why not? They've got enough money to support muzzies and illegals, while taking the natural rights of its citizens away. We saved Europe's ass twice. Third time is not the charm. If they can't defend themselves, then they don't deserve to thrive. We're not the policemen or the bank for the rest of the world, although Europe has been using us as such for decades. As it is, they, like the U.S. are destroying themselves from within. I'm just glad I'm on the tail-end of my life, and hopefully won't be around when this country fully becomes a third-world commie $hithole. But go ahead, support a corrupt nation 5,000 miles away that has made many politicians abroad, and on both sides of the political aisle here, their family members, friends, and big donors, wealthier than they already are. The only winners in proxy wars, are the individuals who have investments in endless wars. American citizens never win.