These technical friends may exist, but I'd guess most of the people would rather pay 15$ / month to some provider than bothering their friend to set them up with a Plex server, maintaining it, figuring out what file to download ("What is this 1080p, 720p?), waiting for downloads to be done, clear out old torrents so they have disk space again.
These are all things that are fun to "us" technical people and I don't mind doing them for myself but if you have to choose between relying on someone else to keep your setup running or just paying someone and have a hands off solution most people will do that. Don't forget that this is very biased community here, it makes comments like this sound a bit like the dropbox vs a pile of shell scripts post.
I think you're overestimating the difficulty of plex.
There's no real maintenance, you don't have to be very technical to download a file(it's two clicks), and if they don't know the difference between 1080p and 720p they don't care, they've waited for downloads before, and hard drives are so large now you rarely have to clear out them out.
My wife uses plex without any problem and she can't stand technology. But besides an issue which comes up every couple of years it's as simple as click and play.
And you're 100% right most people would rather pay someone to take that off their hands. But if things get to the point where you need 15 $10/month subscriptions and can only buy certain shows from one of the 15 mobile apps which have varying levels of compatibility with casters, more people will start looking at other options.
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.
These are all things that are fun to "us" technical people and I don't mind doing them for myself but if you have to choose between relying on someone else to keep your setup running or just paying someone and have a hands off solution most people will do that. Don't forget that this is very biased community here, it makes comments like this sound a bit like the dropbox vs a pile of shell scripts post.