I came across this article a few years back that explains the issue with it. https://aeon.co/essays/schools-love-the-idea-of-a-growth-mindset-but-does-it-work
Along with that there have been some reports that it appears to be successful, though more studies need to show.
This experiment illustrates a great way of using tech as utilitarian value. I wonder if you've read Cal Newport's books "Deep Work" and "Digital Minimalism" which the author emphasizes of using technologies for beneficial use and eliminating ones that are distracting or useless.
Yeesh, the “what doesn’t kill you makes you stronger” idea has already been proven false. Research (the two links below) demonstrates that people going through hardships can develop unhealthy mental disorders like trauma, not the other way around, and it also doesn’t mean you can naturally develop an immunity towards it. The idea just borders between pseudoscientific and unrealistic.