This artificial womb will save millions of lives each year and prevent millions more from suffering disabilities caused by premature birth.
Your numbers seemed high, so I looked it up.
Preterm birth complications are the leading cause of death among children under 5 years of age, responsible for nearly 1 million deaths in 2015.
Three-quarters of them could be saved with current, cost-effective interventions.
So if current, cost-effective interventions were applied we'd have about a quarter-million lives lost that could potentially be helped by this new technology.
Assuming it would be even more expensive than existing interventions, it would be available in an even smaller percentage of cases than those. But let's say it was equally available. That means ~62,500 lives saved.
It's just a first step. It doesn't need to be a miracle to be worth doing.