You can list it on some decentralized exchange if it is a token, ERC-20, TRC-20, BEP-20 tokens could be normally added to DEX even the team didn´t pay for listing on a centralized exchange. Try IDEX, TronTrade. 
And do you think people will buy unknown coins in Decentralized exchanges?? Maybe yes, but a lot of people will prefer to buy coins which listing in good centralized exchanges such as Binance, Okex, etc. If the team keep using free method listing, the project will die very soon