The point of the video is not so clear, maybe it's why reinventing the wheel again and again and not coming up with a good wheel once again.
First what I like of React vs (example) jQuery: despite the complexity a React (or Angular or whatever) application is infinitely more maintainable than the corresponding jQuery one. I converted one to React when I didn't dare anymore to fix bugs in a jQuery monster I created.
However, wrestling with dispatch, props, Object.assign, actions etc can't be the right way to do it. After all these web applications are the same thing we were doing in the 90s with VisualBasic or similar systems. Replace disk access or local Access dbs with JSON calls over HTTP, not a big difference and yet, coding a React app is a miserable experience. I think frontend developers should be paid twice as much as backend ones: they do a much more difficult job. For sure I don't want to do frontend development: it's not an efficient way to make money.
Some context: I'm mostly a backend developer now and I'm spending a few days working on a React frontend every two or three months. So I'm a little too rusty every time I start working with React. That doesn't help but I can't help feeling that code as complex as this smells of wrong architectural decisions. A collegue told me that Vue is much more pleasant to work with. I could give it a try if I'll ever have a personal project needing a complicated frontend. Server generated HTML is fine for everything else.