Now i am wondering is it true? like really BTC is involved in P&D schemes because Wash trading is another term for P&D schemes and both have the same purpose to manipulate the BTC trading volume to control its price for their own benefit.
Some of the regulated trades are subject to pump and dump, what more the one that is unregulated. Bitcoin just like any other altcoin are also subject to pump and dump. Though as the price of Bitcoin increases, it slowly gets away from this pump-and-dump scheme.
I disagree with you about wash trading being the pump and dump scheme. Wash trading is trading between the same group to increase the trading volume of coins or tokens. Having a huge volume has benefits to the project. If they get into the top 10, they are easily seen by other users, and that is free advertisement for the project. While the pump and dump scheme has another motive and that is to profit by building up the price of the coins then dump to gain profit. They often repeat it so they buy at the bottom making their position stronger with a larger amount of coins and profit from the pump-and-dump scheme.