Internet myth.
They used to say the same thing about Panasonic plasma TVs. I bought one of the earliest 42" Panny plasmas, it's nearly 20 years old now and still doing sterling service up in the bedroom. Not a hint of the dreaded burn.
I have an LG OLED computer monitor that often sits with the same screen on, also not a hint of burn. Superb screen.
I would recommend OLED, the best deepest black, best contrast and all round best affordable screen technology right now. (Writing this on a wafer thin Samsung Galaxy Tab S5e tablet with the most gorgeous AMOLED screen which for this old pensioner, who used to fix old valve CRT TVs for a living, is the most astonishing technology - out of a sci-fi movie...)
Just because it says it on the internet doesn't necessarily mean it's true.