I don't need to have an "argument", since it's not an overwhelming opinion that valorant isn't mechanically demanding. I agree that it's less than cs, but more than other games. If you really want me to, I can mention that valorant has movement abilities that throw you off, counter-strafing which adds to movement skill and the spray patterns for the rifles. Again it's not obvious, it's your opinion. Not everything you believe is "obvious" or "undeniably true".
Tbh you're the one that needs a convincing "argument" since you're pretty much going against the grain in saying valo is not mechanically demanding