You have to keep in mind that the decline in profits is mainly from selling fossil gas, that is the gas not liquid, to the EU. Blowing up oil infrastructure is a new thing.
For the last 6 months the US hasn't been able to give weapons, but there's nothing stopping us from lending satellite and human intelligence to the targeting effort, and giving strategic recommendations based on centuries of experience of being continuously at war. It would be weird if that all didn't produce a positive impact on how effectively Ukraine can fight the strategic war.
In terms of fighting courage and tactical knowledge they've been doing it all on their own, yes, and I'm sure they're better than the US at this point which is saying quite a bit. But I think on things like where to bomb the refineries, the US already has lots of footnoted maps and diagrams drawn up that saved some time and increased the impact.
(And the happy synergy of "Hey you know what would help this war effort? If you did a bunch of long term damage to Russia's economy in ways they can't sanction-dodge their way around" "Hey that's a really good point" is a fun thing from the US's perspective, I'm sure.)