On OLED burn-in (technically pixel-wear):
I have OLEDs in most rooms and I haven't experienced burn-in. However, I don't watch TV news channels as a routine. My main use-case is gaming, TV and movies; so there's a diversity of content. With this in mind, I wouldn't anticipate any burn-in on my sets, but your mileage may vary. For what it's worth, one of my LG OLEDs is used primarily as a gaming PC monitor so it doesn't get any special baby treatment. I just use it as I would any other display, bearing in mind my intended use-case.
If your main use-case is to watch the news, or to display static elements on -say- a computer; OLED isn't for you; and -to be honest- wouldn't recommend a high end TV (including QLED offerings) for such a use-case anyway. Something far cheaper would suffice.
It's also worth bearing in mind that -as with all displays- there is a panel lottery. Always buy from a reputable store. My most recent OLED acquisition, a 65" C8, had terrible vertical banding which was visible in everyday content (ie, not just on a 5% grey slide). Thankfully John Lewis carried out a screen swap and the replacement is much better. If you get severe banding on an OLED, or severe DSE on a QLED, push for a replacement; whilst some picture defects are normal, they shouldn't be evident in everyday content.