Maybe it,s me, but I don,t even see a difference betwewn 720p and 1080p most of the time. My TV is 1080p for sure. Once I thought a video was 1080p, but when I looked up thr video statistics, it was 720p.
I notice an FPS drop for a second on MK8 Wii U sometimes though.
Perhaps your TV has not very good picture quality?
I can tell you my tale regarding resolutions.
A long time ago I had a crappy 1080p 27" monitor from LG, the cheapest one that, that I used on my PC.
On that monitor it was not such a big difference to watch either 720p or 1080p.
Afterwards I got a 27" iMac, that had a 1440p IPS monitor, whose picture quality was quite better, and it was not about the resolution, but the contrast and color quality.
In that monitor watching anime 720p was a PITA, it looked quite blurry in comparison with 1080p.
Now time passed, I am using a good 55" 4K TV, and here watching 720p is even more of a PITA, then watching 1080p is OK but still looks kind of blurry.
In this TV I can see very well the difference in quality between a ripped/compressed movie (or a Stream from Netflix) and the 1080p version directly from BluRay (that looks quite better).
Also 4k HDR movies look quite better than 1080p from BluRay, you can tell the difference.
What I mean, you ability to tell the difference or not depends a lot on you display quality.