I have 120Hz on my phone and the difference is remarkable. But I'm still sceptical. I just wonder if rendering at 120Hz then averaging the two frames to display

I have 120Hz on my phone and the difference is remarkable. But I'm still sceptical. I just wonder if rendering at 120Hz then averaging the two frames to display at 60Hz would have the same effect. It seems like a pretty simple demo to set up (if you know how). Does this exist somewhere? To convince me that real 120Hz is actually worth it.