So why are they so often concentrated on the PancakeSwap exchange? It's very simple, because of the ease of listing on this platform, anyone can place their coin there and completely anonymously. Perfect conditions for scammers of all kinds.
Some projects that are startup are really gonna depend on dex like pancakeswap since the payment for cex is so high and expensive. You are right that mostly project can easily list there so as to other dexes on other chain. Since its a dex, a decentralized one format. If theres too much restriction or requirement we cant call it decentralized like big cex are doing upon listing. I may not comfortable with the project he have but he got a point about pancakeswap. No dex on bsc can match this, and it pretty well known on the altcoin ecosystem which I am aware too. Ive been using it eversince so I knew it is the top dex for bsc and its pretty popular even its swarmed by scammers.
It is also worth bearing in mind that if a project originally appeared on DEX at the same level as pancake, it is unlikely it will be further traded on the top centralized services. This happens very rarely. If you initially had no budget to launch it on a well-known exchange, it is unlikely that this budget will appear in the future. I can not remember a single well-known project, which would have started its path, first with DEX of the same level as pancake, and then got a listing on binans, kukoin, etc.