I decided to go OLED vs QLED when I had both in front of me to choose. QLEDs are nice but at the end they're just LEDs and don't match OLED picture quality to me.
About burn in, starting 8-series (B8/C8), OLED TVs have a bigger red sub-pixel, the one that tends to burn in first, to alleviate the problem. Also has a auto logo dimming that dims the area of persistent logos and HUDs to avoid burn. 2018 and 2019 models are way safer from burn in issues than old models, and you see it when you look around other sites and all burn in cases are from 7-series and below.
Of course that doesn't mean they're 100% burn in safe , it's always going to be a minimum risk with an OLED set. That doesn't mean you're gonna have burn in in a year. Rtings tests (mind you, with the 7 series) have shown that sets are pretty safe from burn in even in gaming conditions, and HDTest just wasn't able to get burning with a E8 with their stress test.
Rtings burn in test with 7-series (models not as safe as 8/9 series)
There are concerns about OLED long-term performance due to the possibility of burn-in. We bought 6 LG OLED C7s to play real, non-altered content. It should give you a better idea of what to expect depending on what you watch on your TV.
www.rtings.com
HDTvtest burn in test with 8-series
We investigated the risk of OLED burn-in by displaying varying content 20 hours a day on a brand new LG E8 OLED TV for more than 6 months.We found no sign of...
www.youtube.com
At the end, every TV will have risk of something, my first LED TV has dark spots on the TV and my second also got them, and a LED ended up dying. Second lasted me like 5-6 years and now it doesn't show images, first still works but yeah...
Still, if you think you can't make peace with the burn in risk of an OLED even after all the safety settings OLEDs have nowadays, it's better to get a QLED or Sony LED that just being worried all the time for your OLED. These LED TV are also aamzing sets on their own.