Updated: I think you are totally right. Feel that too. "Then what?" Then Trump would blame the Democrats more, and even some on his own side if he felt like it. Then there would be more acrimonious talk. And more conflict.
And who gains from more conflict? Trump and Musk would revel in it. More conflict would distract from the actual serious damage they, even without a shutdown, have been able to get away with.
However there has been more and more pushback. The courts, which would be at least relatively out of action in a shutdown, are still fully in play, and in the deportation area some legal experts are saying clearly that the Trump administration has actually defied judicial orders.