But unlike an NES system, if your septic tank develops a problem you now have liquid and solid waste flooding your yard and home, and your toilets, sinks, and showers are useless until it's fixed.
I feel like the failure mode for electronics is "randomly catches on fire" which can be just as devastating, if not moreso. Nobody has ever died because their toilet backed up. Their house burning down in the middle of the night is a different story.
People die from diseases caused by sewage, but it's usually a downstream issue.