I'm going to do my best to answer this question in good faith, @Spankytoes.
It seems like you're okay with the war in Ukraine degrading the Russian military, you just think it's silly for the US to spend money on someone else's problems when we've got things to fix here at home. Additionally, cutting US funding might spur the EU into fully funding Ukraine's defense, meaning that we have our cake and get to eat it, too. Ultimately, though, even if it doesn't work out that way, the worst thing that happens is that Europeans get pissy about having to pay what you see as their own bills. Is this synthesis correct?
It seems like you're operating under a few misapprehensions.
First, your use of "empathetic enough" seems to imply that you think we're giving Ukraine support because we're trying to be the good guys, and protecting the weak is what the good guys do. It is what good guys do, and that's a great PR benefit, but if that was actually what we did, we'd be intervening in every humanitarian crisis worldwide. We don't. The US isn't heavily involved in conflicts in Myanmar or Sudan, for example, even though there's a ton of similar horrible shit going on. We do a bit, but it's nothing compared to our support of Ukraine. Why not? Because helping there would cost money, many Americans probably can't locate Myanmar on a map, and most importantly, we don't really give as much of a fuck. Sure, we can broker a talk or two and send some strongly worded letters, but we're not handing over F-16s.
So why the interest in helping Ukraine? Well, there's the obvious: it fucks over Russia, which frequently openly opposes US interests. They look immensely smaller on the world stage than they did before the start of this conflict. Other countries aren't as interested in their military tech, and they're less willing to pay heed to Russian interests. There are myriad reasons why this conflict is bad for Russia, and the more trouble they have with Ukraine, the less likely they are to do horrible shit like it in the future and/or cause other problems for us because they're busy spending their entire GDP there. You seem okay with this, but think it would just be better if the EU got off its collective ass and took charge of its own security, and all that could happen on their dime.
This leads to your second misapprehension, and it's a biggie: you seem to think events on the world stage like this happen in a vacuum. The United States didn't spring into being as the sole world superpower. We got there because we could outspend everyone else. We're the fucking Joneses. A single carrier strike group can take on entire countries' militaries. We have 11 of them. They are expensive as fuck. You think we need all those just to patrol our coastal waters? We have them so we can project power when and where we decide, and we don't really care what anyone has to say about it. This is true not just militarily, but economically and culturally. We are the world's reserve currency. We make the TV and the movies that people watch. McDonald's is ubiquitous. What the US wants, it generally gets, and if another country doesn't like it, too bad. They can go drink a Coke and be sad on Facebook about it.
Being seen as the world police is, for the most part, great for the United States. Countries give a shit what we do and say. They're polite to us. We get the friends and family discount. We can pull together coalitions to do, well, pretty much whatever we decide to do, even if they think it's a dumb idea. This is good for the US, and It makes us even richer - furthering our advantage - and it makes us more secure. Pulling back from the world stage lowers our importance to everyone else. And if you think that this one incident can't directly impact us, European stocks closed at a record high today. Why is money moving to the EU? Because people are investing in Dassault, and not in Lockheed. And the US stepping back from something that the EU - one of our biggest customers - thinks is important means that they'll just need to go make their own shit. We don't actually want them to. We want them to buy our shit and talk like us and think like us. It means we can keep getting our way.
Given all that, why in the actual fuck would you want to lessen our involvement in world affairs? To save some pocket change that is mostly going back into our own economy? When we do things like support Ukraine, we're not wasting money - we're making smart investments.