This is touching on a philosophical debate that is well-recognised in psychology: Categorical vs. Dimensional models.
It's true that individual traits on the wheel exist on a spectrum in the general population but having one or two traits does not make you "a bit" of a condition that requires the presence of a specific cluster.
If you have 1% of "sensory issues," you are not 1% autistic. If you have sensory issues but zero social communication deficits and zero repetitive behaviors, you have zero autism. You simply have a sensory trait.
To be autistic, the "pigment" must be present across the entire specific cluster of domains. The wheel model shows you can be "high" in sensory needs but "low" in support needs for speech, but you must still meet the criteria for the major domains.
The cutoff is not arbitrary. In medicine, cutoffs are based on functional impairment. In psychology, a cutoff isn't arbitrary if it marks the point where a person can no longer function in society without support.
Everyone has blood pressure; it exists on a linear range. But we don't say "everyone is a little bit hypertensive." There is a specific threshold where blood pressure starts to damage your organs. At that point, it becomes a clinical condition called Hypertension.
Everyone gets sad (a trait), but "Clinical Depression" is only diagnosed when that sadness reaches a specific intensity and duration that stops you from functioning daily like eating, sleeping, or working.
Autism is the same. Having a "level" of a trait only becomes "autistic" when those traits cluster together and reach a threshold that changes how the brain processes information entirely.
While diagnostic criteria can evolve, "significantly impacted" in a clinical sense isn't about a mood - it’s about functionality. In a clinical setting, "impact" means inability to maintain employment or education without specific accommodations, inability to navigate social nuances without intense "masking" that leads to burnout, physical distress or "shutdowns" caused by environmental stimuli.
This is a measurable struggle to survive in this world, not a subjective mood. The fact that the traits are presented on a wheel or a range is irrelevant to the fact that a diagnosis identifies a specific neurological configuration that differs from the general population.