How did getting out of high school early go for you? I'm finding that high school is seriously lacking. To supplement, I've been working on my computer science major at a local community college. Unfortunately, doing both college and high school is extremely time consuming and I've been looking for alternatives to high school.
Depending on what you want to do and how overqualified for school you are, a GED is a valid alternative to graduating IMO. That said, you potentially lose a lot of social interaction and sports/clubs which I found to be the most valuable parts of high school.
Personally I was easily able to get 3650 on the GED (out of 4000) which is enough to automatically get into state schools. I have no clue how it would work at a more prestigious school, but at the time that really wasn't something I was concerned with.
I don't feel qualified to say whether it was a good idea because I dropped out after I ended up in foster care (long story, my parents kicked me out after I told DHS about some incidents). Regrettably I wasted several years after this doing nothing but smoking weed and playing video games due to a general lack of motivation. I'm back working on stuff now after quitting games altogether - splitting focus is apparently an impossible task for me.
