Can't I just use my phone to shoot a video?
Can't I just walk instead of drive?
You can. But having a professional team saves valuable time and is way more convenient.
It will be like trying to learn how to drive for the first time vs just calling an Uber.
Too much valuable time to learn how to use a camera, mic, editing software, effects .....the list goes on.
As a business, your time is the most valuable asset. It would be better to prioritise what is more important and outsource the other stuff.
This would save you time and the headache of DIY.