Advice like that above is honestly terrible for newer developers, I believe. It feels insurmountable for many people, myself included. I simply don't have the brain capacity to:

A. Read an entire language's docs front to back. As you mentioned, maybe if it is some small, silly thing but for something like Python, Java, JS, etc... no fucking way. My brain would constantly glaze my eyes over. There is so much.

B. Retain the information I just attempted to read. Again, there is so much. It's insanely unrealistic for most people, I would think.

New developers see advice like this and immediately feel like they aren't cut out for this because people make this nonsense sound like something 'YOU MUST DO' to be a good developer. It's toxic, in my opinion. Maybe not intentionally so, but it really can kill a person's excitement.