What kind of workplaces should I join if my goal is to run my own biz?

I'm currently a software engineer at a high-growth company. I have learnt a lot at this place. The pace is fast and there is the pressure to always deliver, and sometimes, fast. On some weekends, I may have to start reading up about a new technology that I have no experience with so that I can use it in the coming week. Other times, I work long hours or into the weekends so that I can finish off my part. Nobody explicitly say I should do that. But I can feel the pressure that if I don't, I won't be able to meet expectations and deliver the OKRs. My mind is often lingering with thoughts about how I should design a certain logic or whatever work after office hours or even on my bed before I sleep. It's not like there is a switch that I can flip and switch my mind off from work. It doesn't help too when I know I've to continue in a few hours when I wake up in the morning.

My current job is quite draining and I have little time for myself. I joined a high-growth company because people have advised me that these places are good for career growth. They are better for learning and look more attractive on my resume. The pay is also much better. However, it's either I'm mentally weak or it seems like these companies need much dedication to them.

I have always dreamt of starting my own side hustle and perhaps running a small little business of my own. I don't have a full plan for a biz yet though I'm always thinking about it. At present, I'm teaching some private classes as a side hustle and I love it, but it has been very mentally exhausting with my current day job. If my goal is to eventually run something of my own, does it make sense to continue hopping between high-growth companies for a better pay cheque and "career" growth? Or would it be better that I settle for an old-school and less cool company and have a better work-life balance but risk jeopardising my career and track record? Has anyone been through this and has any advice for me?