I remember back in my younger -- renting -- days routinely seeing (and signing) lease provisions that facially required me to have renter's insurance. Which I never bought.
I understood at a general level why a landlord might want a tenant to have insurance. Generally it benefits the renter; for example, if their stuff is stolen, there's some reimbursement. But that might also marginally help the landlord. It might make a lawsuit for inadequate security on the premises less likely, might mean the renter can still pay their rent, etc.
However, I also thought that the landlord's interest in this regard was incredibly low. The real reason these provisions were in there, I thought, was simply because the landlord could insist upon them and the tenant wouldn't really object. Instead, they'd simply sign and refrain from buying. As I did. The landlord wouldn't care at all, unless the tenant became a problem. At which point the landlord might then seek to evict them on the basis of the alleged "breach" of the insurance provision.
My sense in this regard was heightened by the fact that no landlord of mine ever sought to verify that I had renter's insurance. If they cared, they would have cared. And they didn't.
The Appellate Division apparently has a similar sense. Holding that the failure to procure renter's insurance isn't a "material" breach of the lease.
I can see situations in which the converse might be true; for example, when the insurance is broad and when the landlord uniformly checks to make sure the tenant maintains it. But that's not the case here. And, I imagine, it's not the case nearly anywhere else either.