This survey, as i read the words in the OP, purports not to be a broad survey of preferred online content creators per se, instead only a subset being those on YT. As such, i don't find anything objectionable or dubious at all in the poll. Future polls might enquire about other channels, which IMO would be equally fine to ask.
That said, whilst i like fetching quick music memes from YT to assist with my incorrigible habit of going OT in threads, privately my only real YT viewing with any regularity is a suite of Nixers whom over time i've chosen to feel are semi-decent.