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.
Not necessarily. It’s directly integrated into the program and platform that most PC gamers use, meaning it doesn’t require any third party software and is probably easier to use. Personally, Geforce’s solution stopped working reliably for me a long time ago.