It's usually Samsung people talk about with regards to spying on Smart TV, and reports saying they send regular screenshots home for analysis.
I don't know if LG does the same, but in terms on ads in the display I ... never really found it to be anything.
I sold my 55" LG OLED highend model last year when moving, but except for a "recommended app"-showing on the main menu I don't recall any nag-ware. I also found the smart TV features to beat most, if not all, dedicated boxes in speed and usability and preferred it to Apple TV.
What bothers me most on the Samsung TVs is that there are ads in the menu. It's one thing to see ads in a website or other content that is "free" and need to be monetized. But a TV in which I paid for doesn't make any sense.
The argument often made here is that the tv is being sold cheaper and then the value lost is made up with ads. My Samsung TV was pretty cheap compared to others but I just pointed it at my Pi-Hole and don't have that annoying ad anymore.
LG webOS is still one of the better experiences on smart TVs for sure. It is generally smooth with good app support and experience and like you said limited built in ads.
While not perfect it is the system I like the most if I have to use a smart TV. I do still prefer an Apple TV 4K though.
I had been keeping my LD up-to-date but with each new update there was an additional service with its own privacy agreement with a name I'd never heard of.
Same, there are no ads on my LG TV that i can see, unless the occasional recommended app (which at least on one occasion, for Stadia, also told me I'll have a free few months if i sign up now).
I have a Samsung TV but don't use the smart features. I was annoyed by the ads to because it would also change the order when switching devices. Furthermore, I found online that not accepting the privacy terms would remove all apps and ads, this indeed works great.
I don't know if LG does the same, but in terms on ads in the display I ... never really found it to be anything.
I sold my 55" LG OLED highend model last year when moving, but except for a "recommended app"-showing on the main menu I don't recall any nag-ware. I also found the smart TV features to beat most, if not all, dedicated boxes in speed and usability and preferred it to Apple TV.