Have been sporting a 4K LG CX48 OLED since ~Sept, 2020 best monitor decision ever. I've got two HDMI out cables, 1 going to my gaming rig and the other for my Macbook where I do my work as a developer.
I haven't noticed any burn-in or dead pixels. You need to set it up for success, enable all the burn-in prevention settings the monitor provides (static image darkening, pixel shifting&cleaning). It's also a great idea to do other things such as sleeping the monitor after 1min if inactivity, no screensaver (or just black), black desktop background, hide taskbars, etc
edit: to add, i have the monitor mounted to the wall and about 1" above the height of my desk[1] - this puts the center of the screen directly at eye level
