Whether witches and magic actually work, or if it does work, could it be proved scientifically, is a very different topic and I'm not asking about that.
What I know is that people who claim they practice witchcraft, and claim that they can manipulate and "posess" other people do exist today. We don't take them seriously but, if we did we probably would persecute them as well. Did groups like that exist during the highpoint of witch trials (around 1580-1630)?
No -the Witch Cult Hypothesis as proposed by Margaret Murray has been disproven. For more information on the Witch Cult Hypothesis, see What are the historical roots of modern witchcraft? Is there a tie to the practitioners of the Salem Witch Trials?, with an answer by u/badskeleton; Was Margaret Murray's "Witch-Cult" hypothesis ever widely accepted by historians or was its prominence only due to Gerald Gardener's use of it in crafting Wicca?, with an answer by u/AncientHistory.
You may also be interested in What exactly was historical European witchcraft and why was it considered evil? Does it still live on today in modern times and if so, in what form? Does it relate in any way to Wicca?, which has answers from u/sunagainstgold and u/AncientHistory.