First of all. I'm playing on 4060, so your fps can different from mine. You can see fps on comparison picture bellow or in full resolution in upper left corner.
Screenshots are from SoC but CS has the same settings.

AA - Anti-aliasing, AO - Ambient occlusion (SSGI,SSAO).
All comparisons was made on max settings in 4k. FSR Sharpness set to 50%.

Here quick comparison of all AA, AO, FSR settings.


For full resolution and better comparison click link.

MLAA On/Off
https://imgsli.com/Mzg0ODc4

FSR Quality/Off
https://imgsli.com/Mzg0ODgx

SSAO: HBAO+FSR Quality/ FSR Off
https://imgsli.com/Mzg0ODgy

MLAA SSGI FSR:Native / MLAA:OFF SSGI:OFF SSAO:HBAO FSR:OFF
https://imgsli.com/Mzg0ODg0


From this comparison you can see that you can play on low in 4k with 130 fps.

4k Low preset vs Max preset (FRS:Off)
https://imgsli.com/Mzg0ODg4

Here comparison 4k vs 2k (my monitor native resolution is 2k).
https://imgsli.com/Mzg0ODg2

In conclusion, as you can see just by turning off anti-aliasing and cranking sharpness to max, that every video and guide recommend, you can't fix blurry image. Resolution also have big impact on image quality(2k vs 4k comparison). If you have high-end PC you can try to play in 4k on max settings. For every on else i recommend to set 4k(if you have 2k display), 2k(if 1080) LOW / MED preset with AA:Off, FSR:Off / Quality.