In my family, 2 S8s were purchased, and both exhibited burn-in within a year. My son's more than mine, but it was there. Then we both got S9s, and stayed with both for a while. My oldest son's lasted until last summer, but his had a crack from drop after just 1 month that finally caused the screen to stop working all those years later. My S9 was given to my youngest son for has first phone and he's still using it today. About 6 years later and no noticeable burn-in.
So, Samsung at least changed something about those screens between the S8 and S9 to make them much more resistant to burn-in.
I do not know anything about any other manufacturers.