There are lots of sources online that talk about how if you are saving your retirement money within a tax-sheltered account (401k, 403b, etc), you are likely better off with mutual fund investments instead of deferred annuities because annuities typically have higher costs, and because you're already getting the tax savings anyway.
Annuities, of course, do have retirement benefits once they are "annuitized," in that you can guarantee a fixed income stream.
My question: doesn't this suggest that the best option would be to invest in mutual funds within a retirement account, and then right before retirement, transfer all the funds to annuities if that's desired? Why invest in deferred annuities any earlier than that?