It would have been useful if the NYT had clarified the strategy being proposed by President Trump and Republicans in this piece headlined "'let Obamacare fail,' Trump says as G.O.P. health bill collapses." There is no reason to think that Obamacare as written into law with the Affordable Care Act would fail. The exchanges are actually working pretty well in the states with Democratic governors committed to making the law work. The problem of insurers dropping out of the exchanges leaving no competition is overwhelmingly a red state problem where Republican politicians have sought to sabotage the program.
It is also worth noting that often repeated claim that the system is suffering badly from a lack of young healthy people signing up, as implied by this Washington Post editorial, is badly confused. The number of uninsured has actually fallen by more than the Congressional Budget Office projected, so there is no story of a massive problem of people not signing up for insurance. There is a problem that more people are still on employer provided insurance and not in the exchanges. Since these people are relatively healthy (they are mostly working full time and many are older, meaning they would pay higher premiums), their loss to the exchanges may be an issue.
However, the arithmetic shows that more young healthy people signing up could not make that much difference to the program. Suppose another 2 million overwhelmingly healthy people signed up for the exchanges. This would be a massive increase, since there are probably not much more than 2 million young healthy people who are not currently insured. (They have to also be citizens or legal residents to qualify.) The average premium for a bronze plan (presumably what healthy people who don't really want insurance would buy) is $2,700 a year. If we assume that insurers would pocket half of this money as profit, that comes to a net gain to insurers of $2.7 billion a year.
We are supposed to believe this is what determines whether Obamacare sinks or floats?