"Wheel Spacers , wheel adapters" are used to reduce the rearspacing or offset of the wheel. The same can be accomplished by purchasing new wheels with less rearspacing. Many aftermarket wheels have less rearspacing than OEM and give the same wider stance by reducing the rearspacing or negative offset. No difference between this and adding wheel adapters.
While it is true that it is theoretically possible exert increased load leverage with a wheel that has other than a 0 offset in most cases a reduction in rearspacing is a reduction in available leverage for a wheel with a great deal of rearspacing. Pretty cut and dried for a rear axle. In a straight line that applies. That said the scrub radius is increased. This is the radius or arc of the wheel as it turns. On the front there will be more effort in turning and the components used to turn will be subject to increased resistance.
Lots more debate on the subject here:
Rear spacing, offset , wheel bearings, scrub radius
Yet another rearspacing debate...
Wheel spacers got a bad rap from the old slip over the wheel stud spacers. Those could be a problem. That exerted stress in the axle wheel studs. Today's high quality billet wheel adapters are extremely durable and reliable. Rock crawlers to Sprint cars are using them as well as daily driven offroad warriors.
My last truck had 1.25" on the front and 3" on the rear. I put just over 100k on that truck with no issues. My Avalanche has 1.5" on the rear.
In my case I want the increased track width on the rear , better clearance on the inner fenders during articulation. I want to stay with stock wheels for affordability and availability. No worries here
In the end it is your decision. The debate has been going on for years
If you do go looking... you want a billet stock that matches the diameter of your wheel to axle mating surface. You do not want to decrease this area. Look for good quality billet stock. Matching wheel studs is helpful. Hubcentric is a bonus if you have the choice, however use some anti-sieze at that interface. Oxidation can occur when two dissimilar metals meet. Anodized are less prone to this.
You may find some other tips here:
Ordering wheel spacers / adapters ( comparison and review )
Be informed , not afraid
it is your choice.