My parents are getting a new tv, and are asking for recommendation. I think all I can influence is the brand/model (not realistic to propose rpi and more complex systems). I instinctively avoid google/android and lean towards anything else open source, so probably LG WebOS… But I had bad luck searching for more detailed comparisons. Maybe you have experience or opinions?
Depends entirely what they are doing with it. If they are using services with DRM, e.g. Netflix or Disney+ I bet you will be out of luck because that pulls out an entire ecosystem, driven by Google, which is based on selling ads.
“not realistic to propose rpi and more complex systems”
If they have to install it, probably not. If they have to plug it on the HDMI port, power and optionally Ethernet honestly things like LibreElec or Kodi are pretty well done. Heck even a very young kid (talking not even 5y/o) can manage that (I’ve seen it, repetitively) or even start VLC to connect to DLNA server as long as it’s properly setup.