Are bank CDs a better option for retirement than putting my money in the hands of an investor?

As a planner who doesnt work for a bank or investment company, I'd like to address your question by saying "it depends" and both conservative investments and some growth is necessary to sustain a long post-retirement portfolio.

Back in the "old days" when conservative investors had the option of CD or bond yields that at least kept up with reported inflation, moving retirement funds into less volatile options like those was a no-brainer.  With today's ultra-low interest rates, it's almost impossible for a consrvative investor to find something that pays enough  interest income to sustain their needs.  If you settle for todays 1.5% CD rates over 30 years of retirement and 3% inflation, you'll need a very large starting wealth ase to survive it.

My thought is to maintain a larger, but not overdone, concentration in equities than traditionally has been suggested, perhaps focused more on dependable dividend paying businesses that can sustain economic downturns relatively better than the market overall.  Then instead of moving the majority of a portfolio to CD's and bonds, move 5-6 years of expenses not covered by Social Security, pensions and annuities to short term high quality bonds, CD's and cash.  Sacrifice yield for safety there, as that is the bucket to draw from if the markets droop during the first years of retirement.  If the markets don't swoon, slowly dollar-cost average back into the base investment portfolio over time.

Do you have to have an investment advisor to do this?  If you are content with returns that match the indexes, you can build a well diversified portfolio using no-load funds and ETF's along with either a "robo-advising" or portfolio rebalancing advisory service at the large discount brokerages.  If yoiu need more assistance, seek a fee-based unbiased CFP professional or an advisor whose commissions are clearly stated and offers more than just investment monitoring.