Are fluted knives a gimmick?
I am assuming by "fluted knife", you mean what is sometimes called a granton or hollow edge knife, where there are indentations in the blade intended to reduce sticking or adhesion to the food:



Except in very specific circumstances, this feature makes very little difference, those circumstances being:


Carving large roasts
Cutting large and tough vegetables such as certain squashes


For most use, it simply doesn't matter.   In fact, the thickness of the blade tends to have more of an effect than the voids in most cases.

Except in the specific case of a slicing knife (which is a specialty knife that most beginning cooks have no need for; you have also in other questions indicated you are a vegetarian where this knife is primarily for slicing hams and other large roasts), this is not a feature I would look for: