I've had a LG OLED65E6V since 2017 and no burn in that I have noticed, and its used probably about 3 hours a day.
Also have a LG OLED55B7V since 2017 and again no burn in that I have noticed, and that is probably used about 5-6 hours a day.
No gaming though, just Netflix, Prime, Youtube streaming stuff. Maybe a Blu-Ray every now and then.
Now, I specifiy "that I have noticed" I've not gone out of my way to look for it, but in my books if its not obviously visible then its not a problem and I genuinely haven't noticed any visible burn in.
Both 5 year warranties, both now expired (the 55" 4 days ago

) Probably get massive burn in, then burst into flames on Christmas morning now.