I have a 200+TB library for my Plex and jellyfin instances. The Roku was just a family friendly launcher and remote. I bought them when you could still disable ads in the secret menus and most of the Roku BS is blocked by a pair of piholes, but I've gotten annoyed chasing new urls to blacklist.
It's DRM for the other app bullshit that becomes a hindrance for going the Kodi route. There really isn't a good alternative that I've found. Linux boxes will limit some services to 720p and jt's mostly baseball and local news programs that I'll lose.
For the news, I need to look at something like hdhomerun or something else I can pair with an OTA antenna.
For baseball, not much other than the absolute mess that live streaming sports is. Doable, sure. But a pita and sketchy last I looked into it. My season ticket comes with MLB.tv, but the irony is that I'm "in network" so all my teams games are blacked out for me. I had previously created a VPN tunnel and routed one of my Rokus to a different state to watch it. But it's not a user friendly experience.
For games, I already have a batocera box running on an old dell thin client with way more power than a pi, and it has Kodi on it. But the UI/UX still sucks.
DRM. They don't like how open Linux can be so to combat people using it for pirating their content the companies restrict it.
For instance, Netflix is capped at 720p on Linux unless you are on Opera, apparently.
https://help.netflix.com/en/node/30081