Why is it advantageous to avoid a divorce trial?

Because the divorce goes through the courts uncontested. That means the spouses, having agreed to end their marriage without a finding of fault, have successfully negotiated the terms and conditions of support and custody and the division and distribution of the marital estate.

For one, it probably means that they have saved themselves a great deal of money because if they cannot agree between themselves, a judge will have to decide for them. That makes for legal bills, not to mention all the enervation of battle. This is called a contested divorce.