Marker vs Static footsteps
What are Marker footsteps?
Marker footsteps are used for characters with running animations. If the animation includes a marker named "Footstep" with a value of either "Left" or "Right" then the footstep audio (and or effect) will play at the same time, giving you much better syncing
What are Static footsteps?
Unlike marker footsteps which rely on animations, static footsteps rely on pure timing and estimation. Static footsteps also rely on the character's walk speed, which still gives you a natural effect.
What's better?
Marker footsteps are undoubtedly the better option as they're immediately synced to any speed.