(In 2020) Some economists said bitcoin is a solution looking for a problem. Read https://sg.finance.yahoo.com/news/economist-bitcoin-is-a-pyramid-scheme-204217615.html

The people who bought into digital currencies have a keen interest in recruiting others to continue purchasing these currencies. The more people that get involved and buy into crypto, the higher prices will go. That means those at the top, the early buyers, will become even wealthier. In fact, 1,000 people own 40 percent of the entire Bitcoin market.

For any ICO, the founders can dump their coin holdings and abandon the investors.

Some reputable retailers now accept BTC, partly because the owner owns BTC.  Imagine you operate a reputable retailer and have bought some BTC. You can make one low-risk move and announce online that you accept BTC as M@E. Actually, 0.01% of your customers would bother to use this M@E, but 60% of them would see your announcement. Your high visibility and your marketplace reputation would be a boost to the bccy.

Similarly, anyone with an audience, with a mass following can make one low-risk move — buy $1000 or $1 worth of BTC, and announce to the world that “Am long BTC.” If you search online you may find many celebrities did that.

Q: does gold have a pump-n-dump tendency?
%%A: I don’t think so. I think PnD mostly affects new securities with questionable underlying values.

— a new token is like a new stock.. https://www.trality.com/blog/how-crypto-pump-and-dump-work points out that “The people who are developing a project are as important as the idea they are working on. Many investors consider the management team to be one of the most important parts of an investment thesis. Keep in mind that people can lie about who is working on a project.”