That's 70s logic with no tech behind it. Hell just stack some freeze plugs with a hole in them in a Maglite body. No machine work needed. You can even jb weld a hex nut of the right thread pattern on the end so you don't even have to weld.you're right but you will also have thousands of very skilled guys with real equipment that will be able to turn these out for much much much cheaper. Prices are gonna tank. suppressors are cheap in european countries where they are legal to the point that they are viewed as a disposable object.
At the end of the day its just a threaded tube with baffles. It does take precision to get it good but its still pretty close to metal lathe working 101.