I don't disable VSync for FPS. I disable VSync because it reduces input lag.

Actually, to reduce input lag. You don't want vsync in multiplayer first person shooters, that's for sure.

v-sync is a workaround, VRR is the solution.

As others have pointed out, there are numerous problems with v-sync — in addition to input lag, f you want to drive (for example) a 100 Hz monitor, the GPU will need to consistently deliver ≥100 FPS, or you'll repeat frames and introduce jitter.

This means you don't need to consistently hit 100 FPS to experience ≫60 FPS refresh rates (without jitter).

The problem with vsync is if the game would be 59 fps on a 60hz monitor, it's going to be presented at 30 fps because it's going to barely miss the vsync every frame. This creates large fps instability when the game runs around the monitor frequency.