What more could have been done by God or anyone? And the answer is, that nothing more could have been done that would have obtained a better or different outcome.
God provided truth. God provided perfect righteousness. God provided perfect justice. God provided man with the right to choose. God provided salvation and eternal life and eternal blessings that defy the imagination. What more than that, could have been provided? There is nothing more.
God provided the threat of eternal condemnation in the Lake of Fire. What worse judgment could have been threatened? And again the answer is there is no worse judgment or condemnation. The Lake of Fire is worse than anything imaginable and beyond worse.
And then that question, of why did the vineyard produce worthless grape when good ones were expected?
And this question does not mean that God does not know the answer, but is for our benefit, and pushes us to think and understand the reasons for human failure in the spiritual life.
And why does God ask the obvious? Because people disregard the obvious, and absorb themselves in their own delusion of self-justification. Thus they ignore Gods mandate to study daily, to study under the instruction of an instructor, to confess, to reside in fellowship, to apply spiritual content to their daily lives, to grow up.
And instead, people live in an emotional sphere, justifying their own invented self-promoted views of spirituality, pursuing their own works for Gods approval, or simply rejecting God altogether and either ignoring God or pursuing something else.
And thus they fail.
What more can be done? Nothing more. Abraham once told the rich ruler who ended up in Torments, that even bringing him back to life would not convince others of their errors. They have the scriptures already for that. If anyone will not believe truth, then they will not believe even miracles.
Jesus, who is truth, brought numerous miracles for over a period of three years, and was still rejected.
Truth is doctrine, and can be learned only in one way, which is by means of a daily study and becomes the foundation and substance of the entire spiritual life and essence of the individual.
Without doctrine you have no legitimate building material for the spiritual life, and there is no alternate substitute. Not sincerity, not emotion, not pretense, not alternate views, nothing.
End of study