Alternate view: Almost everything in life is ridiculous when you view it with cold logic. It's utterly ridiculous to put golden balls on a fake tree in your house every year, but due to societal constraints most people in Western societies do it.
Your SO probably doesn't want a logical gift, she wants something sentimental that makes her feel that you care about her. For some people, that's an expensive rock with no utility, for others it might be something different. But applying logic to what's ultimately an emotional, illogical affair isn't always productive.
Django is the gold standard for consistently pushing out reliable, well documented open source software without any marketing fluff or other bs. The amount of value the team is adding to the world can't be overstated.
It's amazing that this kind of simulation can be done so accurately with javascript in a web browser. I have no idea how it was implemented but the computational load must be nontrivial.
Strangely I think it also helped me become a better doctor. I think it helps you develop a natural insight into probabilities and people's reactions to them, which in a roundabout way helps in diagnosis.
Your SO probably doesn't want a logical gift, she wants something sentimental that makes her feel that you care about her. For some people, that's an expensive rock with no utility, for others it might be something different. But applying logic to what's ultimately an emotional, illogical affair isn't always productive.