If you want to learn how to write, you mainly need to read more, and fixing grammar and punctuation is an automated thing nowadays. If you feel like you're getting expert writing feedback from a high school teacher then you won't be writing any novels any time soon anyway.
> we should conduct a moonshot project to build a homeschooling technonanny that uses enough electricity to power the Eastern Seaboard so we can educate our kids without human interaction
Actually, unironically yes since you only have to do pretraining once. A model that can then run inference locally on smartphones and is used for many years would amortize its creation cost though the utility it provides in a few years. It wouldn't even have to be AGI tier, just good enough to work with.
A single teacher educating 30 people vastly underperforms 1-1 tutoring. It's a "good enough" system and it doesn't work very well for most people, it's just the only thing we have. Hell most of it is just following a fixed script that repeats every year, answering a few questions and grading based on ground truth.
A personalized teaching system that knows your interests and skills would be able to motivate and explain far more effectively by adapting the script to you in pace and difficulty. Being available to you 24/7 for questions and having a personality you like would certainly help too. There's this 11 year old video [0] from the ex-teacher CGP Grey that turned out to be pretty prescient and elaborates a bit more on the general idea.
All of this could even be done sustainably, running training during peak solar hours, excess wind power and the like, but as long as there's demand it doesn't make sense to leave your expensive and rapidly depreciating GPUs idle. And there's demand because people have this misconceived notion that AGI is somehow winner take all, making it a race where everyone's flailing about like a headless chicken. In reality whoever gets there first will have a short first mover advantage for half a year and then everyone else will replicate their work, and probably an open source version a year and a half later tops.
[0] https://www.youtube.com/watch?v=7vsCAM17O-M