Why does a 720p video on a full hd monitor look acceptable, but a 720p game on the same monitor looks like a terrible "soap" that makes your eyes run out?

Question

Monitors

Watching videos on YouTube from a full hd monitor even at 480p is not annoying, but playing at 720p or God forbid less is simply impossible, this is a mockery of the eyes. But why is this happening? And plus a small question, where did all these ladders come from in games, couldn’t the developers immediately draw a little more pixels so that the ladders were one pixel (hence not so noticeable)? Is anti-aliasing with its own algorithms more profitable in terms of performance, especially on modern hardware? For video, no anti-aliasing is needed and there are no ladders.

Answer 1

In order:
1. Movies have blurry every frame (try to take a screenshot of a video that has motion - get soapy), so 30 frames at 480p look acceptable even on a FHD monitor (the brain itself lines them up in a video sequence). In games, the frames are not blurry (therefore, you can take a high-quality screenshot) and therefore the minimum frame rate of 50 frames is playable for games (hello to console players), otherwise you will see a slide show;
2. Ladders will be even at the highest settings if your monitor has a small number of pixels per inch. This is a physical limitation, so very often there is no need to even turn on anti-aliasing - there will be ladders anyway;
3. On cheap monitors, there are ladders on the video.

Answer 2

In order for the ladders to be one pixel, turn on the game on a FullHD monitor in FullHD resolution. Why are you playing 720?