How did you justify quitting your day job?

Let me just show you two pictures. Before and after.
https://imgur.com/a/NkyBquS

The day job was making me miserable. Ruined work-life balance, too much stress from the management, expanding our team’s operation and responsibilities while failing to recruit more people (the management set high expectations for candidates and rejected everyone, while our team of 2 engineers was overworked for more than a year). Being a total spineless dweeb, a typical bullied kid at the school, I just sucked it up. The last straw was us winning an award for our project, after which we were told that the interesting part (developing a framework) was over, and it was time to grind.

My family didn’t take it easy. I came from a working class family who were brought up in socialist USSR and believed that one should endure and just diligently keep doing the work and be thankful for having a job. Besides, my salary was, like, 10 times higher than theirs — our country is poor but the IT industry makes a better buck by outsourcing for the US and alike. So my decision to give it up, despite being on a brink of depression, was a shock to everyone. The only relief was that after quitting I didn’t just become a couch potato, but started indie hacking right away and assured them that one day I would catch up. I had some savings due to relatively high salary and no social life, so that helped too.

After 3 fruitless years making stupid projects and one mind-changing crisis, finally I’m onto something.

In my case it was the disparity between the value I was creating for my employer, and the paycheck I was seeing on the other side. In some cases I was receiving less than 10% of the dollar value of the work I was billing out.

The bigger justification was time management, and the ability to focus on the things I think are important. If you're employed full-time, the best hours of your productivity every day are not under your control. For some people this is an acceptable trade (or, they're forced to stick to the job they have thanks to debt or bad contracts). In my case, I decided I'd rather find a way to live that let me voluntarily plan most of my day.

I quit my job in April this year, and as of this month I'm a (technically) successful freelancer, in that I've built up a little runway, have happy customers, and can explore my own projects now. I'm still doing the same work I was doing this time last year, but now I have to compromise on my time management a lot less.

My salaried job sucked, big time. Hence the quitting :)

Had no alternative income, no functioning side business. Just a little savings in the bank and the passion to set out on my own.

Should be a no brainer if you have saving for few months (which you should!). I needed a break from last job and was realizing that if I want to do something on my own I need the time to focus on it. Work and indie hacking is horrible. Anyway the easy part is (for me at least) that I can find a job if I want to.

Started nights and weekends yea.

Be confident about your cv in the labor market, Saved up 2 years runway, exit on good terms with your current employer.

I've tried multiple employees to understand that corporate job and employment feels like loads of bullshit. Even I managed to gain the system -- move up the ladder, have a decent pay... It felt like I can't take it anymore, everything seemed pointless.

I just sold everything and moved on, without clear plan, but with savings. I became a freelancer to sustain myself financially, but I would really love to have my own product to work on.

At some point I decided there was no other way to learn the required skillset. I think I've learned more in one month about what it really takes to build and sell a product than the entire 8 years I had worked as a salaried employee. Necessity is the mother of invention after all.

The other thing is that the worst that happens is I go back to being a salaried employee after I run out of money.