
Nasim is a young computer scientist, hoping to work on the Human Connectome Project: a plan to map every neural connection in the brain. But funding for the project is cancelled, and she ends up devoting her career to Zendegi, a computerised virtual world used by millions. Then, 15 years later, the Connectome Project is revived.
He also has a whole bunch of short stories on the same topic. Some assume reader is already familiar with concept of sideloading, as it's explained in the passing:
1. Bit Players: https://www.gregegan.net/MISC/BIT/BIT.html
2. 3-adica
3. Instantiation
4. Uncanny Valley (available online)
Other:
1. "Reasons to Be Cheerful"
2. “Learning to Be Me”
3. Closer
I feel like the rest of your comment kinda proves my point more than it proves the opposite? Forcing yourself to engage in cerebral activities simultaneously utilising different motor, language and problem-solving skills is GOOD.
I'll say though that quoting Greg Egan is putting the cart before the horse, because his brand of end-point transhumanism sorta assumes that we WON'T destroy ourselves through Huxwellian dystopias before getting to that level of technology.
Read Egan's Zendegi for a more realistic take for how that technology integration will go down.