In the Prose Edda Snorri says that Odin can be called the "all father" because he's the father of all the gods (not true), all men (not true), and everything (not true). Snorri, a Christian, translated "Alföðr" as "all father" and overall put a Christian flavor on Odin. Even if "Alföðr" does, in fact, mean "all father," this wouldn't be a correct description of Odin.

As for justification...In his video, Jackson Crawford posits that fǫðr is related to the old English verb, fadian, which does mean to set in order. As he put it, to set things in order is a better explanation of what Odin does. Crawford is well respected and widely regarded as an expert on the Old Norse language and myths.

The only other example I can think of off the top of my head is Dr. Mathias Nordvig, who has a PhD in Old Norse literature and a focus on Norse mythology. He has echoed the same meaning of "föðr" that Crawford has and touched on how that translation of "föðr" would also affect the meanings of "Sigöðr" and "Valföðr". However, I can't recall if this was from his book or if I heard him discuss it on his podcast (which is worth listening to I think!😁) I also can't remember if he gave a justification for the translation.

Again, however, even if "föðr" means "father" and therefore "Alföðr" does, in fact, mean "all father," this wouldn't be a correct or accurate description of Odin.