This is really 100% not true. Fifo vsync does nothing bad at all with VRR and frame time within VRR range, and you can avoid the additional latency added when it would cap fps simply by adding an fps limiter. Likely depends on CPU frame time variance. It's quite good in Fortnite (some/many atrocious stutter events ignored) and frame time graph even can be a flat line with AL. I don't like it vs. CAS shader in ReShade or configurable RCAS in games with FSR 2. It makes the image already look rough at minimum 10% setting.