Also startup accelerators usually work with businesses that already exist. It's actually a good analogy. If you already know a little bit about coding and computer science a bootcamp can really help. If you don't have the drive to learn programming than a bootcamp can leave you with a huge skills gap.
My first business failed miserably. I had no business training and no one in my family who'd ever run a business. I was just overwhelmed all the time and never had advisors to reach out to (a problem YC students wouldn't have)
In hindsight, I know what I did wrong and what I should have done instead.
I'd say it took me at least a year of failing before I could gather my bearings and understand what was going on.
I never learnt how to code though, but I know a lot of technical stuff.
So I legitimately thought that "hey, I can learn to code in a few months"
Nope. 12 weeks is hilariously less to truly understand coding.
You can, at most, mimic the actions of the teacher.
It took me quitting, then months of idle rumination to understand what a recursive loop could be used for.