Pretty much this. The author really seems to live in a bubble. Additionally, if you're anything but a software developer, e.g. you're a process (chemical) engineer, this advice doesn't work in the slightest. New chemical companies don't open up in a bedroom every year, so you can't hop around that quickly. This applies to every engineering profession except for software development (/...engineering)

What about feelings of regret later down the line? I already regret not doing more in my life in my teenage years (I spent it all studying alone). I cannot imagine what feelings of regret I would have if I spent all of my 20s working non-stop.