May be because you are not familiar with Addy Osmani and his work. He is known for his very high quality performance optimisation work for web for almost a decade now. So anything he has read, edited and put his stamp of authority on is worth reading.

I do not know the guy, and I do not care who he is. This really is not "slop". I can attest to the validity of almost all of his points based on my own career. And even if he used ChatGPT assistance to help with the writing, the content clearly was not invented by ChatGPT. This is valuable advice for people in our industry.