Because it seems like a relatively recent development that off-grid solar power solutions have become affordable and mature enough to not suck on average.
Around 40% of the population of Nigeria (a country of 200+ million) does not have access to electricity. The per capita electricity consumption of Nigeria is _two orders of magnitude lower_ than the US.
> Around 40% of the population of Nigeria (a country of 200+ million) does not have access to electricity. The per capita electricity consumption of Nigeria is _two orders of magnitude lower_ than the US.
You asked how long "all my life" I've spent only partially reliant on the power grid is, and someone else has provided you some context (that I actually mean all my life, which you can probably infer to be longer than two decades at least).
As to the second half of your original question, solar power is not the only kind of backup power that exists.
Because it seems like a relatively recent development that off-grid solar power solutions have become affordable and mature enough to not suck on average.