You are correct in that why would the US destroy NATO. The entire point is that the people in power in the US have decided that EU is now subservient enough to the US (and since the blowup of Nordstream 2 energetically dependent too) that they will simply do nothing when the US takes Greenland in whatever form that takes.
Greenland becomes strategically important when arctic ice melts and new shipping routes open between China and Europe, and the US plans to control this more directly than it does now.
Trump does not have the power to decide geopolitical policy of the US, if he went against US interests he would quickly be removed. This is not Trump’s personal designs (maybe the messaging is but not the core events), this is the US betraying yet again its allies as it has always done.
I clearly won’t convince you and I don’t think you’ll convince me either, so let’s each guess based on their own ideas:
A) Trump destroys NATO through whatever form of invasion of Greenland
B) The US gains greater control over Greenland above what they have now (whatever form it may take) and EU keeps bootlicking the US
I’m betting on B), as a tankie. I wish it were A) because NATO is close as it gets to literally Satan, but I don’t believe the powers in the US are going to waste the EU influence in its most subservient moment in decades.