His argument is of the form "if we get a Thing(s) with these properties you most likely get these outcomes for these reasons". He avoids over and over again making specific timeline claims or stating how likely an extrapolation of current systems could become a Thing with those proporties.

Each individual bit of the puzzle (such as the orthogonaly thesis or human value complexity and category decoherence at high power) seems sound, problem is the entire argument-counterargument tree is hundreds of thousands of words, scattered about in many places.