By fully funding them. The return from a lifetime annuity bought at 65 is just marginally higher than a reasonable expected safe return from the same investment. (A lifetime annuity pays out on the basis that the provider needs to guarantee an income until you die, so if it returns so much that it eats too much into the capital, it'll be unprofitable for the provider). At the margins, the expected remaining life years of someone at 65 in a developed country is long enough that you can't safely offer that much more without eating away too much at the capital too quickly.