I quit my job last month, and so far, it seems it was the right decision.
What really pushed me over the edge was just realizing how bored I was at work, and it wasn't just a slow period - it was systemic. The projects I'd fantasize about spaced out commuting home genuinely excited me, but then I'd snap out of it as soon as I got home and realized I had 4 hours to eat, bathe, and maintain relationships with friends and significant others. I was scared to think about losing my paycheck, especially because I'm not pursuing these projects as potential revenue streams - really just for the sake of exploring and learning new things. I'm fortunate enough to be in a position where my only financial obligation is rent, and as a software engineer, a few hours of freelance work per comfortably covers that.
I'm not advocating everyone go quit your jobs, because I realize everyone's situation is different. But life is too short to be bored as shit.