Javascript is it bad practice to return an object that is passed by reference

Let’s say I have this function in javascript:

function foo(a){
    a.item = "four"
    return a
}

b = {item:"three"}
b = foo(b)
console.log(b)

Since Javascript is a call-by-sharing language there is no need to return a, the object b would have the same final value with the below code:

function foo(a){
    a.item = "four"
    return a
}

b = {item:"three"}
foo(b)
console.log(b)

Is it bad practice to use return b for better readability even though it is not needed

Are there any downsides to returning the object?