Even multiple ISPs might not help. I remember a DC issue where they had two physically separate ISP attachments from different sides of the building. Cable cut

Even multiple ISPs might not help. I remember a DC issue where they had two physically separate ISP attachments from different sides of the building. Cable cut takes out ENTIRE DC. Why? While the ISPs were different, at one (farther upstream) point they were both leasing fiber that ran through a single conduit -- so you need understanding of the physical structure of the network, not just "different ISPs".