I've looked into it several years ago and a product was trialed, but basically you can't insure events that are bound to happen, you need to bolster the insurance pool.
I and a few others don't have any issue abstracting all topics into their economic realities, including the marriage concept that the state offers in its entity catalogue. I think many more people could do that as well, it is just convenient to deflect and pretend marriage isn't about that, convenient for typically one party in any case.
It's not like someone is forcing you to get married. Also 41% as a top line number doesn't tell the whole story. Among college educated Americans the rate is ~29% and falling year over year.
Also prenuptial agreements are a thing for a reason.
maybe at 2% there could be a viable divorce insurance product and the terms of the contract wouldn't have to be updated by legislatures
but at higher percentages an insurance product is not possible, and we need a better contract, laws, and court behavior