The biggest thing for me that pushed me over the edge was thinking, how will I get a mortgage? All this applying, 100s of applications, even if I land a job it's not stable. Maybe it pays more, but I'll be laid off in a year or 2. Then back to 100s of applications while my mortgage is ticking away.
I have a friend who worked at Adobe for 5+ years as a senior AI researcher. Has a PhD in compi sci majoring in AI. He got laid off last year and couldn't find any work. I witnessed it. He gave up and started doing a side hustle thing on a video game. It's just not stable, and thats not how I want my life.
I don't see much overlap between mechanics and cars honestly. Everything in a car is modular. If it doesn't work, you replace it. Car tuning has some level of tech. Kind of. But that's an entirely different field that people specialize in, typical mechanics cannot do that.