The short version
Motion usually wins on comprehension and consideration. Static often wins on cost per test and on channels with hostile playback conditions.
What is really going on
Motion carries sequence — it can show before and after, cause and effect, which static cannot.
Static is cheaper to iterate, which matters when you are still searching for the message.
Some placements degrade video badly; email and certain display inventory still favour stills.
How to handle it
Find the message with static tests, then invest motion budget in the winner.
Always design the first frame as a competent static ad — many impressions never play.
Compare on cost per qualified action, not on view count.
The takeaway
It is a sequencing question, not a rivalry. Static finds the message; motion scales it.
