there may be slight competition, but from a viewers point of view, I prefer YouTube and DTube because of the way they are laid out. it is easy to find exactly what I want to watch. I don't want "my provider"" telling me what I want to watch, i want to be able to go and find it easily. SO uinless they fix that, I don't see it being a big challenger.
Also I want o to be able to watch on my big screens at home and without a proper web interface for both uploading and consuming, i feel it is a non starter.
RE: Instagram launches IGTV - YouTube Killer?