The analysis decides it, not the product. If your income sources already cover what you want to spend, you may not need an annuity at all, and we will say so.
Where one usually earns its place is filling a specific gap: covering the base expenses so the rest of your money can stay invested, or holding funds you want growing without market exposure. An annuity is generally a portion of a plan rather than the plan itself. Anyone recommending all of it deserves a second opinion.
Fit is also not a one time decision. Most indexed contracts let you move between crediting options at each contract anniversary, and the caps and rates attached to those options reset. The allocation that made the most sense at issue may not be the one that makes the most sense three years in. Almost nobody changes it after the application, largely because nobody tells them they can.
So we review it every year: what the contract actually credited, how the options renewed, and whether the allocation still lines up with what the money is meant to do. It is a small piece of work that adds up over a contract's life, and it comes with the relationship rather than as something extra.