- I had less time to do things I actually wanted to do, like studying.
- Didn't make me better at coding, how could it?
- It didn't teach me anything about finance, how could it?
- Didn't make me better at "time management" and other pseudoskills. Yes they are pseudoskills, people throw them in the conversation to pretend you are getting something.
You know what makes people good at their job? Doing their job. This is why you run into the people he mentions, they are ok at some other thing but they are spending their time doing a shitty job instead. They are running to stand still, and then running some more to leap off the treadmill. This is also why plenty of not-particularly-bright kids grow up to grab the prestigious jobs. They didn't have to do shitty work for no pay, they used their comfy middle class upbringing to connect with the right entry-level roles, and took it from there.
So then you get people who somehow manage to do it. They work at McDonald's flipping burgers during the day, and then they somehow learn how to reverse a linked list at night, and lo and behold it pays off and they get a job at Google. Everyone points at them as says "look, it can be done".
Don't be fooled. If you do two jobs (flipping burgers and learning to code) you are putting everything on the line in for a better future. If you get run over by a car, you will be lying on your deathbed thinking "why didn't I go out with my friends instead of memorizing quicksort". If you make it, think of all the disillusioned people who gave up whatever little free time they had for a dream that almost never comes true.
This is of course if you think of jobs as a pure money thing. If you like doing algo stuff (I like it a lot somehow), maybe you don't see it as a second job and you actually get some kind of satisfaction from it, which is what I'd hope for most people.
But for shitty jobs, most people simply do not think they are satisfying. They are exactly what we should work on automating out of existence.