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?
how do you remote control HTPC?
wireless keyboard and mouse is not a real solution. all other such devices that you mentioned used a handheld remote controller
There are a ton of remote controls with USB out there. Including ones that are remote control sized with a mini keyboard, presenter style air mouse built in, or even using remote controls on your phone (KDE connect is awesome for this).
I do use a wireless keyboard/mouse combo. A very very small one. But I very rarely use that. I push all content through plex which can be driven easily with devices like firetv and have remotes. The htpc does the real work, but I don’t interface with it directly (generally speaking).