Comment by IncRnd

What you reference is that commas are used to set off non-restrictive clauses, where the meaning of the sentence is clear without the additional clause. Though, the non-restrictive clause provides additional description of a word in the main sentence.

Such as:

Sometimes writing for money, rather than for art or pleasure, is really quite enjoyable.

Other than that, many people have come up with many writing styles. We mostly seem to be able to understand each other, so we are "all good".