No, seriously: sourcing external data puts you at the mercy of the providers (somewhat mitigated by SRI). What makes self-hosting so unappealing? (I do understa

No, seriously: sourcing external data puts you at the mercy of the providers (somewhat mitigated by SRI). What makes self-hosting so unappealing? (I do understand that it's a breaking, backwards incompatible change w/o notice - that's what would anger me)