Each bad move on a solo is death. For driving, biking in traffic, it has to be a series of bad circumstances to mean death.
The soloists who achieve notoriety are either pushing the limits, or seeking adrenaline, which skews the stats, especially when you check the number of them that passed doing non-climbing activities. It's not particularly fair to compare that demographic to the average folks who bike in traffic every day.
Soloing well within your limits is like riding a bike on a quiet road, there are things that can go wrong, but something extraordinary has to happen for it to be serious.
Soloing close to (or outside of) your limits is like riding a bike on a busy motorway. The margins for error disappear and mistakes are far more likely to be fatal.