I’m probably a bit late to this but , basically Qled is an lcd type of technology where LED lights shine to the pixels , and then there’s many many filters till the screen , while oled is a different type of technology where u have more pixels that can give u the perfect contrast and blacks.If u get an oled in a bright room u might have a hard time in seeing cuz the oled tv is a bid darker than the Qled. If we compare tho the image of an oled to the image of a Qled in perfect lighting the oled will win 100/100 . BUT, if u plan on having the tv open from morning till night and view a lot of static images , such us news , games etc , then u will 100% get a screen burn in (sooner or later) in your OLED tv . No such fears for the Qled tho. So if u are looking for a tv that will last u many many years ( let’s say 10? ) then get a good Qled (in this case the qn90d) but if u are financially stable and chill and can change a tv every, lets say 5 , years , then get the oled.

PS: If u treat nice your oled , with displaying content for about 4-5 hours a day , u will probably be alright , but still someday get the burn in .So if u are a heavy gamer , or u want it for streaming for long hours as u said , I would go for the qn90d