That is 100% subjective.
For instance, I can easily argue that breaking kernels and writing drivers for obscure hardware does not add any real value for society as a whole.
However, playing and socializing with people does create value for society, specially in this day and age where people is evermore alone, if only in reduction of antidepressants ;)
Anyway, parent said obscure hardware, so hardly useful for most people. And it sounded more like a personal activity, it is not clear he/she did publishing or upstreaming or blogging about it.
By the way: actual drivers for complex hardware are nowadays mostly written or maintained by companies.
Right, but there are instances where you can train for that live demonstration, like CTFs in self-contained environments like virtual machines.
Seems pretty similar in scope to a video game to me. I think you're more accurately complaining about games that provide little value beyond the skinner box. What about stuff like Shenzhen I/O, Factorio, etc? You could even make strong case for RTS games teaching transferable skills.
There’s games all around us if you look. I like to play the “I broke my kernel and my entire system is fucked and now I gotta repair it” game or the “write a driver for some obscure hardware” game or even “demonstrate a vulnerability exploit on a live system” game, all which lead to greater value creation and self fulfillment superior to defeating some imaginary creature.