Emergency abortions required for health reasons are often needed when things go wrong, and when that is the case it might need to be performed either soon or immediately. Being in a state that opposes it might delay the decision in ways that injure or kill the mother.

Non-emergency abortions required for health reasons - that is, when there is significant risk but it is not unfolding yet - also happen but being in a state that opposes abortions at any level in general might make it difficult - doctors not willing to suggest it to avoid risk to their business, those around you refusing the need and convincing you that it would be bad, not to mention having to plan a medical trip to a foreign location to get it done - and in turn put the mother at risk of injury or death through inaction.

Does it somehow make it less relevant to fix a cause of death because more people die of other unrelated causes?

Far more people die in accidents than any other causes of death in the U.S., seemingly only beat by cancer and heart disease. That doesn’t make every other cause of death any less troubling or worth fixing, and it certainly does not mean that one should hold back existing treatments for “lesser” deaths or injuries.

Any avoidable injury or premature death is one too many.

Economic hardship results in orders of magnitude more all-cause mortality, making it the more important problem to solve.