I have an old 60 inch 1080p TV from the early days of smart tvs. It has a built in app for plex and youtube, a remote that works as a pointer, it's insanely slow but it has zero ads and I'm never ever getting a newer model.
Yup. My 58" 4k LG TV has a bunch of apps (we only need Netflix and Jellyfin), and the only ads I've seen are in their apps, which don't need to be opened. It's a little slow and apparently can't even handle Jellyfin over HTTPS, but it works well.
My SO wants a bigger TV, and I'm dreading looking through the current market to find a decent replacement. I'd really like OLED and for it to be a few inches bigger, but it seems everything has ads and spyware out of the box. Screw that...