Pixel response time has less to do with motion fluidity than motion clarity. If frame times are less than pixel transition times, you get ghosting. If the refresh rate is too low for a given overdrive setting, you get overshoot, or inverse ghosting. Both can standout as an after image, halo, or smearing, and reduce clarity.
Motion smoothness is primary dependent on frame rate and consistency of frame intervals (both in terms of when the scene is submitted and when it's finally displayed). Blur can actually increase perceived smoothness, at the cost of clarity, by blending frame transitions together.
Latency is another important issue, which depends on frame rate and pixel response, to a degree, but is also heavily influenced by the game's render queue and any processing lag the display has (which can be extremely variable).
Personally, I tend to run everything uncapped and unsynced at as high a frame rate and refresh as I can manage, with as short as render queue as possible, to get what I feel is the best of all worlds. Good smoothness, good clarity, and negligible input latency. VRR is nice in theory, but in practice a sufficiently high refresh rate (I personally stop being able to detect tearing as refresh rate gets significantly above 120Hz...144-165Hz is borderline in some cases, but 240Hz+ means I never really see the advantages of syncing frame rate with refresh rate) renders tearing imperceptible, and VRR usually has costs in terms of overshoot...very few displays have overdrive modes that are ideal across the entire VRR range (even my Samsung G7 has obvious overshoot ghosting near the lower end of the effective VRR range that is completely absent at higher refresh rates).
