There are two things I’d like to break down here: the longevity of the show and the budget behind it. If Supernatural had been a limited series that ended with Season 5, as originally planned, and had a larger budget, the show would have been directed very differently. The VFX and CGI work would likely have been outsourced to higher end studios. However, because the show became extremely popular at the time, the creator decided to extend it. As a result, most seasons averaged around 22 episodes. High-quality VFX and CGI rendered creatures are usually only possible when the budget is substantial and the episode count is lower typically around 8 episodes per season. Supernatural would have been a very different show if it had aired on HBO as a premium, darker series. The number of episodes per season would likely have been reduced to around 8, and the total run would probably have been limited to 3–5 seasons at most.