Ideally, you would have a drive system for your filament that is:

• lightweight
• responsive
• durable
• does not obstruct or adversely affect movement of the printhead

Unfortunately, you have to choose. You can’t have all of these qualities. Each setup has pros and cons and every 3d printer needs to decide what is best for them or accept what their printer comes with.

A Bowden system mounts the extruder off to the side of the printer frame, allowing the printhead to be more lightweight, which allows higher speeds and acceleration. The tradeoff is that you have a tube that connects the extruder to the printhead, which makes accurately controlling the amount of extruded material more difficult (think trying to turn off a lightswitch with the end of a broom handle).

A direct drive system is just the opposite. You get more responsiveness with your extruded filament, but you are adding weight to your printhead.