I save a bit of gasoline on the 15 or so days I'm without power. I already had solar, so it seemed a little silly sitting in the dark with nothing to run my water pump to flush the toilet. I was also in a situation where the inverter on my solar system had died and the original manufacturer was out of business. There was not a huge cost difference in getting an refurbished identical replacement versus something fancier that switches between house battery, EV battery, generator, solar, and grid tied. Pays for itself in 60 years, if I go by time of use billing, but I arranged to keep net metering so it's more like a 27 year break-even for me in part because my battery system is oversized and expensive.
For rural living, it's worth it, makes a huge difference for us. As an investment that saves you money, it depends, answer is often "no". But it is insured and warrantied. So not really so much of a gamble, most scenarios are covered.