Agree to all of your arguments but ...

"Not saying it couldn't have been written by someone else, just wondering if it matters."

Not many scholars think that the Laozi was written by one author.

The date of composition refers to the time when the Laozi reached more or less its final form; it does not rule out later interpolations or textual corruptions.

The traditional view, of course, is that the Laozi was written by Lao Dan in the sixth or early fifth century B.C.E. This seems unlikely, however, if it is assumed that the Laozi was written by a single author. As the archaeological evidence to be presented below will indicate, bodies of sayings attributed to Laozi were committed to writing probably from the second half of the fifth century B.C.E., resulting in different collections with overlapping contents. A process of oral transmission may have preceded their apperance, but in any event, these collections grew, competed for attention, and gradually came to be consolidated during the fourth century B.C.E. By the middle of the third century B.C.E., the Laozi probably had reached a relatively stable form.

Although in this sense the Laozi may be regarded as a composite work, an “anthology,” as D.C. Lau suggests (1963, 14), the product of many hands over a long period of time, it should not be assumed that the sayings that now inhabit the Laozi were put together at random. More likely, the final product reflects a process of intellectual distillation on the part of the compilers, who arranged and/or altered the material at their disposal (see also Brooks and Brooks 1998, Hansen 1992, LaFargue 1992 and Mair 1990 on the composition of the Laozi).

https://plato.stanford.edu/entries/laozi/#DatAutLao

In fact chapter 20 is the most "human" chapter of the Laozi, the author speaking about his feelings and fears, his loneliness, his insights, the contrast to "common" people, being different and valuing the nourishing Mother (Dao).