The evidence is already in, some people just refuse to accept it, but their loss (or not).
Let's take the Rtings test for example. In the first one where you have the logo elements of varying opacity shown on screen, you can begin to see burn-in starting for the solid logo (100% opacity) as soon as 700 hours in (of that logo being displayed). For 50% opacity, 800 hours in. At this point the 100% opacity logo is clearly visibly burnt in for normal usage. But okay, maybe this is a bit too extreme.
Let's look at Rtings test #2. In this case, burn-in is not much of a concern for most usage patterns except CNN (predictably), where at max brightness burn-in starts being exhibited after 2800 hours. Unfortunately another weakness of OLED becomes apparent. Even though it's not outright burn-in there are clear signs of colour degradation even in usage which is of a slightly more varied nature (FIFA 18, NBC, CNN, American Football) around this 2800 hour mark, with only the one being used to play CoD on being spared.
So what does this mean? It means that for people who are more single-minded about what they use their TV for, and who spend a lot of time on it, and like it bright, OLEDs are going to be with them for a short while before exhibiting various forms of degradation. So if you plan to drop a lot of £££ on a TV hoping to last you a long time, it's probably not wise for it to be an OLED. Here's Rting's take on it: