Once a smart contract is deployed, regardless of it being renounced or not, that contract is immutable, meaning it cannot be changed from its current form. This means that the functions available to an owner wallet are limited to the functions available on the "read" and "write" of the contract which require the owner address. On the Shinja token contract, this would include things such as changing the fees, whitelisting, blacklisting, and a few others. Being on the blockchain, anyone can follow every single action performed by the owner wallet. You can always get the owner wallet from the link above, but on the "Read Contract" button.
With the above in mind, it should now be clear that a contract owner cannot do whatever they like with the contract. The owner can only change what exists on the contract as it stands at the point it was launched, and though these functions are limited, they are important to maintaining good governance over things like:
Changing taxes for special events, such as a "low tax" or "no tax" buy event, or "increased staking tax" event.
Ability to whitelist specific addresses required by certain exchanges.
Ability to blacklist specific addresses, such as scammers. We have blacklisted multiple scammer addresses which has stopped them from being able to access Shinja stolen from our holders.