"Europeans buying oil and gas from russia" -> that is mostly one or two hold-outs that are in russias camp, pretty much like Orban/Hungary.
"Maybe global energy markets are more important than Ukraine and Russia’s war is?" -> yes, they are, but they have nothing to do with each other. Conveniently though, this is the link that Trump wants you to make and Trump is pretty much a mouthpiece for the Kremlin.
> Which capabilities are being weakened exactly? Can you point to specific capabilities?
GP never responded and I don't blame them, but taking the risk that you really do not know and are not 'just asking questions':
Ukraine needs both defensive weapons to stave off russian attacks on their citizenry and offensive weapons to make sure russias capacity to wage war is diminished. Both of these rely to a large (but ever decreasing) extent on foreign countries. Lots of that stuff comes from the United States and even though the United States has not made good on the promises it has made it now also effectively puts its thumb on the scale to favor the Kremlin, for instance by diminishing Ukraine's capability to control its drones and by withholding armaments that were promised by the United States, and paid for by the EU.
If you are even remotely interested in what is going on there this should not be news to you, if it is then you should review your sources.