> I've yet to be saved by an airbag or seatbelt. Is that justification to stop using them?
By now, getting a car without airbags would probably be more costly if possible, and the seatbelt takes 2s every time you're in a car, which is not nothing but is still very little. In comparison, analyzing all the dependencies of a software project, vetting them individually or having less of them can require days of efforts with a huge cost.
We all want as much security as possible until there's an actual cost to be paid, it's a tradeoff like everything else.