The definition of a tiny specific monopoly within a niche is meaningless. If you had 30 different factors to describe exactly what each platform does then each

The definition of a tiny specific monopoly within a niche is meaningless. If you had 30 different factors to describe exactly what each platform does then each of them would be a monopoly in themselves. In any case Instagram is certainly not in a monopolistic position at the moment unless you try to twist the sense of words to fit a narrative.