Yep, what's inside Trust Wallet is called a Dapp. Investors and traders alike can easily do their buys and sells there and pay swap and slippage fees. It's a decentralized system and no one hodls anyone's tokens except the one who has the passphrase or key to the wallet. It's better than trading on centralized exchanges. I trade there using Pancakeswap. It's easy to do if one can over look the fees which have become very high now.

I think what the OP wants isn't even feasible. There's no way he gets to sell Shiba Inu without going through an exchange. It has to be from his exchange (since there's no private wallet for Shiba) to another exchange (that of the buyer). It's as simple as that.