You don't have to invest and maintain them, they are not really any more expensive than lithium and don't take any maintenance, though I do top them of when I pull out gear to test it. I don't believe in storing gear for years at a time, I pull everything out once or twice a year for checks.
Looking at batteryjunction.com and costco.com for pricing, Eneloops cost twice as much per AA cell for 2/3rds the rated capacity. Energizer Lithiums self-discharge more slowly and weigh less. In an extended power outage, I'd far prefer to have Energizer Lithiums over the same number of Eneloops, even if fully charged.
Over time, Eneloops are far less expensive. I use them for a variety of purposes. But for me, Energizer Lithiums make more sense to keep with my emergency gear.