I think a key idea for Ukraine is that a lot of the minerals are in territories Russia is occupying. So, the US has a selfish reason to kick Russia out.
https://www.visualcapitalist.com/mapped-ukraines-mineral-resources/
I imagine such a thing being warped by Trump to mean he will look for the same or a better deal from Russia, for those same minerals.
Anyone over the age of say, 30, or thereabouts has no excuse in the US not to understand what is happening here. Even less if you were of age during the lead up to the Iraq war (this is a figurative you, not literally you).
There is a strong parallel here to the often quoted "curse of oil rich nations". In the case of oil, it's too easy and too much of a temptation to just exploit the effectively free money you can print by selling oil and you end up with dictators and corruption and lack of effort into developing your society for the better good - see pretty much every country who relies on oil exports for the bulk of their income for examples.
Something similar can be said for countries with a large defense industry. It's so easy to boost GDP and provide stealth stimulus just by manufacturing and selling weapons. A patriot missile system is worth literally a billion dollars and supports high paying jobs to all the people designing and manufacturing it, and of course this all trickles down to other workers in the economy. The problem is that unlike say, a billion dollar dollar power plant, it doesn't really provide any real utility to the citizens - especially if it's just sold or given to another country. But it's "easy", and like oil, the temptation is just too high to press the easy button.
Which brings us to Trump. He campaigned on ending the war. But that would cut off the easy button so anybody with half a brain knew that this wasn't going to happen. Both parties like the easy button too much. So Trump needed cover to keep the easy money flowing while being able to save face on reversing course on his campaign promise. Enter the mineral agreement. This whole thing is a boondoggle, we all know that. But it allows trump to keep the MIC gravy train alive under the guise that "but look, Ukraine is going to pay us all for it through minerals!"...some time in the distant future when Trump is long gone. Which of course really means never, but it'll all be long forgotten by then.
The question is how the Russians plan for this eventuality. Hard to say at this point. The Russians are generally pretty pragmatic but if they genuinely thought the US was going to cut off weapons flow to Ukraine then the bluff just got called, so we have to see what comes next.