but not all Exchange Some good exchanges still list many normal projects for money on their exchanges but only exchanges like Binance, kucoin ,FTX , coinbase etc still adhere to their strict rules and regulations. So these exchangers are always able to keep them top position on the Exchanger list on coinmarketcap
That is mainly regarding the bear market. During the bull market there are so many projects that does very well that they are either listed for free just because exchanges want to take advantage of the high volume, or they are just listed with a bit of regulations and rules and that's it, because it means money to list them.
During the bear market there isn't any money to be made from this, so the better exchange you are, the more money you can charge to list a token, and that will result with you making money even with just listing, and could say stuff like "if the volume drops under 10k dollars, we will delist you" and not pay the listing price back.