But he is wrong unfortunately.
It's not about resolution, it's about native resolution.
2 things many PC gamers do is to set the game to their native resolution (whatever it is) then reduce effects in order to have a stable framerate (or vice versa).
Hell that's why I did with HL2 on my old LCD panel and at that naive time my aim was just image quality, naturally after several configurations I learned that the best image quality (notably on a shitty LCD) was with a native resolution. And that native resolution >>> whatever effects I could add in the game.
If we had 900p LCD sceen then I would perfectly settle for that res, but unfortunately my screen is 1080p and I refuse anymore to play at a damaged image quality when so many 1080p are out there.