Here are some difference:
4k TV KS8090 with HL2 on screen
Beware, big size pictures:
720p with MSAA 2x
https://www.pic-upload.de/view-33044376/720p-1.jpg.html
https://www.pic-upload.de/view-33044351/720p-2.jpg.html
1080p without AA
https://www.pic-upload.de/view-33044381/1080p-1.jpg.html
https://www.pic-upload.de/view-33044384/1080p-2.jpg.html
4k with MSAA 4x for fun
https://www.pic-upload.de/view-33044387/4k-1.jpg.html
https://www.pic-upload.de/view-33044391/4k-2.jpg.html
Pics taken offscreen with Samsung Galaxy S6 edge.
Intel Core i7 8700K | 32 GB DDR 4 PC 3200 | ROG STRIX Z370-F Gaming | RTX 3090 FE| Crappy Monitor| HTC Vive Pro :3