Some altcoins or let's say that they are many now that are becoming fake and being soft launched in the market. They're just testing the waters if they're going to become popular and gain volume. But not all of them are fake, we know that there are legitimate ones and are being used by many like the top ones. If you're in the new ones, you'll have to deal with the risk that they bear usually when they come out freshly to the market. So if you have earned like the new releases and they're being listed in good exchanges, you won't call them fake because you earn upon dumping it.
Yes, there are fake ones but how we can filter this type of deal is if a good cex gets to list the token at the long run
The problem is, they will just pay the good cex to gets listed. That's how the world goes today in these exchanges but if you can start to report them even if they have good volume, hopefully that they'll get reviewed and will be considered. But again with these matters, it only takes is money for them to get ignored by being a fake one and then into building a reputation and then volume that contributes to the profit of that exchange.