I have a very well oiled Plex / Flexget / Sonarr setup myself so I know what you are talking about and it's seriously great.
If you set it up for someone it'll work very well but if you have to do it yourself, or ask someone else to do it for you and they don't already have their own setup and offer it to you it's not really an option for most people who don't like to tinker with these things in their free time.
I think we can agree on that it's great for people who'd like to tinker and maybe offer it to their family members, maybe even with something like http://plexrequests.8bits.ca but for "normal" people it's not really an option.
If you set it up for someone it'll work very well but if you have to do it yourself, or ask someone else to do it for you and they don't already have their own setup and offer it to you it's not really an option for most people who don't like to tinker with these things in their free time.
I think we can agree on that it's great for people who'd like to tinker and maybe offer it to their family members, maybe even with something like http://plexrequests.8bits.ca but for "normal" people it's not really an option.