Yes, most of the P&D are nothing but scam groups, they tell you to buy a shitcoin, when you buy the coin it will pump and the owner will take out his money, resulting in your loss. Even if your favourite influencer tells you to participate in a P&D , be mindful that they are going to make money out of your loss.
How do Pump and Dump work?
The owners/admin of the Pump and Dump group accumulate a coin before the announcement of the pump when the general public pumps the coin they sell their positions and cause huge loss to the people who have participated.
The video below shows how pump and dump groups work and how you can make profit out of it, if at all that is possible.