Now, back to the belt or direct drive issue. Technically, a direct drive helps eliminate this negative factor from the equation, so a record player with a direct drive has a much more consistent rotation with a much lesser amount of interference. A belt driven turntable, on the other hand, has a band made of rubber that is pulled around the motor and back onto the platter. If this band looses its elasticity (which it is bound to, since it’s essentially like a rubber band) then the force around the motor pulley would be inconsistent too, leading to a less than ideal quality of music. Replacing the belt itself isn’t cheap as well. Some can cost up to $200.
A lot of modern record players have already switched over from a belt to a direct drive precisely because of this. It works well enough. Then again, it depends on the quality of the direct drive itself. There are plenty of other accessories that you may find useful for your record player. Note however that these aren’t necessary. Dust box covers, stylus brushes or cartridge protectors are literally frills that do not enhance your music listening experience.