Hustle culture is perpetrated by people who have something to sell you. They pretend to be successful until they are; their product is themselves, and there isn't much room in that space. The truth is that it's quite hard to make a passive income equivalent to what you earn from a day job, and it takes time to build. You tend to have to be willing to experiment. Most experiments (like, 95 percent) will lose momentum by a couple percent per week unless you're putting a full-out effort into them. Terminate those, even if they were the ones you hoped would succeed. Others will grow by a couple percent per week. Double down on those, even if they're not the ones you were passionate about; those are the sacrifices you have to make if you want to make the same kind of money.
The truth is: this process can take years and nothing is guaranteed. Plus, your app that makes $30,000 per month might crater due to regulatory changes, competitors, et cetera. Most of the self-styled passive income gurus were independently wealthy already, or at least had the connections necessary to get back into respectable work if nothing panned out (which makes a huge difference). If you're working a regular prole job--even a programmer prole job, which is physically undemanding but humiliating (daily scrum)--you're probably going to be too exhausted to put all that much into a side effort; that doesn't mean you're weak or lazy, but that you're human.
I don't think you should quit your job and focus on your hustle until you're 99.5 percent sure that it can fail (or that you'll start to hate it once it becomes your primary source of income, and burn out) and you'll be alright. This means you need to build the skills, savings, and connections necessary to be safe if you need to run back to your old career.
Life circumstances can also push you in funny directions. I'm (mildly) disabled and (unrelated) almost died in 2019, and the reflections on my own mortality brought me to take time off to finish a novel (out in '23) and go back to graduate school and try for a legit research job... although it'll be several years (if ever, adjusted for inflation) before I'm back at my old TC level, because research pays 50 cents on the dollar compared to corporate garbage (a pay cut that's worth it, IMO) and no one can predict book sales (even the so-called marketing experts in publishing houses get it wrong half the time).
Good luck. It's hard, and the odds of each attempt are low, so you'll probably have to make a number of attempts. Don't trust anyone who makes it sound easy.