I don’t think burn-in is much of an issue on modern displays. When was the last time you’ve seen a phone or monitor with burn-in?
I think it’s still a very real issue, even if it’s less of one than it used to be. I haven’t seen any phones or monitors with burn-in in person, but the only OLED monitor I see on a regular basis is my own, and phone screens pose less risk of burn-in in general, since they’re not getting used continuously for 8+ hours a day, nearly every day.