That’s not necessarily true. It depends on the contract. It's no different than buying a home for 0% down.
In our case, DW/me have a "life annuity" under our SPIA contract. We know exactly what we will receive in benefits (fixed payment, so we can take our monthly benefit x length of guaranteed period). If we live longer than the life projected period, payments continue at 100%. If one dies early, payments continue at 100% to the survivor. If we both pass before the calculated "life benefit period"? Payments continue (either monthly or lump sum) to our estate.
BTW, we know we will receive at least 2x our original premium, if we live or die; more than 2x if we beat the odds.
Again, I'm trying to understand what I give up. It's up to the insurance company (e.g. take on the risk) to ensure I get our contracted monthly benefit.
If they are able to invest and get gains better than I? Great. I really don't care. What I do care is to ensure a portion of my retirement income...