You're approaching this like a debate. You're free to decide for yourself. You're hardly the only person who dives solo, who doesn't bring along redundant air.
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For everyone else in this thread: Hanging out in the "Accidents and Incidents" section most of scuba-accidents seem to follow a "3 strikes you're out" sort of rule; where the only reason the incident became a serious accident was because 3 things went wrong at the same time. One of those things going wrong often is ignoring some standard practice, safety measure, or redundancy. The other two are typically things out of their control, that are improbable but can happen.
As solo-divers, in a sense we "break" one of the common rules/redundancies. However, a self-reliant diver can be safer, by taking extra precautions and redundancies, whether that's redundant-air, monitoring physical/mental state, redundant cutting devices, etc. And of course, there's also what I call the "buddy hazard" which can often be seen any time two divers die on the same dive.
I like to remain at "zero strikes" myself. However, anyone who wishes to start their dive at "1-strike" will be at 2-strikes any time any incident happens.