There's a lot to like here, but, as with almost all 'advice' lists, the author makes the mistake of believing their own hype. They're effectively saying "I am a good developer, I do these things, therefore to be a good developer you should also do these things." It ignores the possibility that there are good developers who don't do those things.
An example is the advice that "Software engineers should write regularly." Why? Can't you be an awesome dev if you don't write? You definitely can, because I've met hundreds of great devs who've never written anything that you'd call 'writing'. Devs who enjoy writing, and get something from writing, should absolutely write things. If you're a dev who doesn't enjoy writing then you probably shouldn't force yourself to do it just because someone said it's what devs should do. Find a different outlet that gives you the same thing other people get from writing.
I’d definitely agree that “software engineers should publish writing regularly” might be off the mark, but “software engineers should be able to write well” is pretty uncontroversial. And being able to write well comes from focused practice, however you get that practice.
One "easy" way of "writing" is to answer support emails / calls. It is almost the same as teaching stuff, only with a more relaxed timeline. I am currently supporting a system (and have been supporting other such systems in the past) about which I know very little. So each time a support request comes in I have to dig, understand, formulate an answer, scrap it, dig again deeper, ask around, etc.
In the end I don't even care if this takes a lot of time, I learn so much in the process that it is absolutely worth it. I would not be happy doing it 100% though, because writing code is really on a different level, but I find that these two complement each other very well.
Corellation is indeed not causation and humans are good at finding patterns where there are none. He might also drink a strawberry milkshake each monday, or pray to the arcane, binary gods before going to work.
However it is okay if someone says: "Writing helped me as a developer. It might be different for you."
Hopping that easily from "works for me" to "must work for everybody else" without a second thought is indeed not reassuring coming from a software engineer where "works for me" is not enough.
Touching on the writing point. Think of it as muscle memory, if you watch people put together PowerPoint slides you see that those who do it regularly can create a solid presentation quickly. As a developer, at some point you're going to be writing some basic technical specifications to decompose a project. Even if you've been only writing to yourself, having the ability to quickly pull together a document that communicates with others is an asset.
I'm nitpicking now, but it's not necessarily "this worked for me ergo do this" – it could also be a sprinkle of "the other skilled software developers I've observed have also done this". It's not much less anecdotal, but it does shift the perspective from "this is what I do" to "this is what I think matters for other people as well, based on my limited observations".
An example is the advice that "Software engineers should write regularly." Why? Can't you be an awesome dev if you don't write? You definitely can, because I've met hundreds of great devs who've never written anything that you'd call 'writing'. Devs who enjoy writing, and get something from writing, should absolutely write things. If you're a dev who doesn't enjoy writing then you probably shouldn't force yourself to do it just because someone said it's what devs should do. Find a different outlet that gives you the same thing other people get from writing.