Anemones are commonly regarded as difficult to keep, but IME the "difficulty" varies tremendously depending on your environment.
Under marginal lighting, the long term survival rate of anemones drops considerably. Under proper lighting, you almost have to try to kill them in order to.
Real world examples of "Oh I've kept them under such and such" isn't going to help you much because the success varies when measuring not only the lighting, but the other equipment and experience of the aquarist.
What I mean is, an experienced hobbyist running an aquarium that is stocked and has equipment conducive to excellent water quality can get away with less than perfect lighting. However, with anemones, outstanding lighting can make up for shortcomings in other areas, (if any
)
So I personally feel that proper lighting (halide or T5WIR) is a necessity, and it'll just make your life easier if you have it.