Saying that something has "never happened" and therefore there is no need to prepare for it is foolish.
Some people drive the same car for 10 years and never get a flat tire.
Does that mean they should remove the spare to make more room in the trunk?
Well, 44 years of scuba here, mostly solo also since the beginning and don't need or carry spare gas tanks around as a rule. Thirty feet is snorkel depth, the surface is my redundancy.
I don't really understand all of this redundancy as of recent years, it kind of has come out of the blue and is largely unsupported by any real need or evidence thereof.
N