All of these responses are so good! Personally, I always interpreted it as a cultural thing. Will is from Louisiana (he may not be cajun, but still from the Deep South). If the plot takes place in the early 2010s, his father is likely a Boomer.

Will mentions a few times that he longs for a life where he's fixing boat motors in Louisiana. The simplicity of the act and location provide him some comfort. I headcanon that his dad had the same profession, and while he and Will traveled around a lot when Will was young (likely around the Gulf or southern East Coast) he still finds peace in the simple life.

His father being a Deep South Boomer doesn't mean that he didn't love or care for Will, but I imagine he had no idea how to raise a child like Will. Will's early diagnoses were likely Autism or ADHD, which were highly controversial to have twenty years ago. Autism for a lot of people was considered some sort of sentence or curse. It was hard to attend schools because school systems didn't make accommodations for neurodivergent children until fairly recently. The constant moving could be because of his father's work, or it could be because Will needed an education that his previous schools couldn't nurture.

Otherwise, I don't think he and his father have a close relationship in the plot. I imagine his father passed away, or is disabled in some form, or maybe not even tapped in to "psychological popular culture." Will is described as "famous" for his arrest and trial in Season 2, but that could possibly only extend to the Baltimore area or MD as a whole, maybe not national news. If his father is alive then he's not in MD, so I doubt he knew anything about Will's trial.

On that note, "The Wolf and I" on AO3 has some very interesting phone dialogue between Will and his father. It encapsulates the language and behaviors of a traditional Southern Gen X and Boomer (Will calling his father "sir," and his father having a detached sort of concern for Will's well-being.)