Do you write an essay when you apply for these scholarships? Even if an essay is listed as "optional," you should read that as "required." Remember that scholarships generally have requirements or guidelines, and they're generally merit based. That means that everyone applying for that scholarship meets a certain baseline, and your job is to make yourself stand out from that baseline.
In your example, you need to think about how many other applicants also had a 3.9 GPA, etc. If it just comes down to numbers, the selection committee really has no way of making meaningful determinations. That's why essays come into play. An essay is your opportunity to say something that sets you apart from other applicants.
That means that the essay should be taken very seriously and not just treated as "a part you have to complete." It's an opportunity to tell your story. One of my colleagues at work just gave a workshop on writing winning scholarship essays, based on our experiences administrating scholarships over the past few years. So many of the essays said precisely the same thing. "College is expensive. It constitutes an economic hardship for my family. This scholarship would make things easier." Anyone reading that will sympathize. The problem is that, if everyone says that, it's no more compelling when you say it than it is when anyone else says it. It becomes a largely useless metric for making decisions.
Reviewers need to hear a more individualized version of that story. They need to why they should select you. Part of that is based on need, but a lot of it is based on plan. By that, I mean that funders will want to know that the resources they're giving out will be well spent. Taking some time to talk about how this funding fits into your larger PLAN will help. Why are you pursuing this degree? What do you plan on doing next? Why is this personal to you?
Think about the things YOU find compelling in a story. They're the same things other readers find compelling, and they need to be a part of your essay. Make the scholarship application your own, so that the committee feels they're awarding a scholarship to a person and not just a name on an application.
Does that make sense?