the good news is that much of the smart app functionality has moved to TVs, all the samsung and LG tvs in my house have full DLNA support, mp3 streaming, spotify, netflix, amazon, youtube, etc apps all built in and they all work pretty well with just the TV remote.
i think honestly a lot of people here just hate the idea of using the apps built into their TV, the DLNA apps on my TVs are pretty good now and I can use my android phone to fully control them and go through my PCs shared playlists etc with ease. I'm sure something like the chromecast also works well, although since I like full 1080p ripped movies it isn't a solution until wireless speeds get better.
You still need to install Plex on your PC to cast the files but i don't have to touch anything anymore on any new TV bought in the last few years