Many with Left side tighter than right?

Why does the Structure need re-setting in the first place?
I notice chiro’s have a belief that if you re-set the Spine, hips and neck, then tension will leave.
Other chiro’s believe remove the tension off the muscle directly, and the Spine, hips and neck re-align on their own.

However - what caused the missalignement in the 1st place? Why is the body unbalanced? or a compensation pattern in the first place?

it could be due to an injury.
It could be due to favouring one side 90% of the time, ie, right handed tennis player.
Could it also be due to Lack of Elasticity in the muscle/sheaths/ tendons? Thus causing a pulling action onto the “main frame” or Skeleton, thus causing compensation patterns, causing miss communication in the CNS?

It can also be, an example, Extreme strong Calf muscle from running, jumping ect, and a weak, underdeveloped Tibialas anterior muscle.