Why not install neck first

Long time lurker first time poster mods please remove if not allowed etc. etc. etc.

When building an electric guitar it's obviously super important to get the neck lined up right. Why not route the neck pocket, install the neck, and then build everything else around that rather than installing bridge and pick ups and trying to meticulously make sure everything lines up? I haven't seen anyone do it that way in any tutorials.

It seems easier to install the neck and then draw a center line based on the neck base everything on that, that way you don't have to worry about lining up the neck since by definition it's already lined up.