Games and other programs mostly load into RAM and run from there so defragging doesn't affect game performance at all. What it can do, your game may load a little faster and Windows may be more responsive.
The defrag function in Windows is good enough for basic maintenance. A paid third party program might run faster or have different optimizing priorities which may or may not show in basic Windows performance. In any case end result between Windows defrag and any other program are very close to each other.
If you dislike the Windows tool, try the free and reputable
Defraggler by Piriform instead of spending your cash.
Note: If you have an SSD, it should not be defragged, ever. Defragging is for spinning platters only.
