I am active on many exchanges and I see coins that are manipulated almost daily. The more the exchange list more coins, the more you will see more manipulations.
Exactly, consider also some projects and exchanges that collect money for random projects before they list their coins. Means, it is a listing fee. I believe that this is very famous in most exchanges. I believe this still exists for some exchanges.
Just take a look in DEX (decentralized exchanges) how projects are being rugged, it's example of manipulations that you can witness live and sometimes happened in just few seconds or minutes.