The reason is already discussed above.
Wich blocks sound better plywood or sheet rock.
Many types of plywood are available that range in cost finish thickness and kind of wood used.
If you use plywood anyway just follow my recommendations on how to dampen the sound when using plywood.
For that reason plywood vs drywall have been the most frequently used material to encapsulate sturdiness to your garage walls.
When it comes to garage walls plywood and drywall serve the same purpose.
Final thoughts on plywood vs drywall soundproofing.
A 5 8 inch sheet of plywood weighs 1 8 to 2 1 pounds per square foot versus 2 75 psf for a sheet of 5 8 inch drywall.
Drywall and plywood are the two primary materials for constructing walls in homes.
Most commonly two layers of drywall are used to provide that extra mass that can block sound.
The garage is the one place that requires ample space and the ability to hold many heavy materials.
This means that the average 4 by 8 sheet of drywall can weigh 20 to 30 pounds.
Thickness drywall sheets perform better than and are more commonly used as well.
A 15 32 sheet of osb is just over 15 making it a bit more expensive than drywall of a similar thickness.
Each has its advantages and disadvantages and which type you use will often depend on what you are using the place for.
If you want more successful soundproofing i recommend that you use drywall instead of plywood.