Although this may be off topic with regard to the healthcare debate, I believe it is on topic within the thread (or at least it’s title) to take issue with the opening lines…
The shutdown isn’t really about healthcare, it’s about partisan power. Its about the Democrats needing to show that they can stand up to Trump and that they can not be completely ignored. And its about the Republicans asserting that they have supreme power and so don’t need to negotiate. Healthcare was just the battlefield that the Democrats chose to make their stand. If in an alternate history the Republicans had unilaterally decided to extend the ACA tax credits in their big beautiful bill. The shutdown would have still happened, it just would have been a different awful action that the Republicans took unilaterally that the Democrats would demand be changed and which the Republicans would be refusing.