Understood, although it's not actually that hard.
That's not the point.
It's also not hard to level the audio in every clip either, but only a fool would design their workflow so they had to do that.
Same thing with focusing, it might be easy, but it's an extra step in the workflow, and when you have to do it dozens of times per shoot, over hundreds of videos, that adds up to a lot of dicking around. And dicking around = annoyance, and annoyance leads to ultimatle frustration and reduced happiness. And all
for no benefit when you can just get a proper camera with a decent autofocus.
When you produce content every day then you get to realise that the little stuff matters.
Example: everyone told me to try Adobe for video editing, so I tried it. Found I had to do an extra couple of mouse clicks
for every clip in my timeline. Hundreds of extra clicks per video compared to my current workflow, screw that, no thanks, so I ditched it.
It's bloody frustrating when you thought something was in focus, take some footage, and then realise in post it wasn't.
It's bloody frustrating when you use manual focus and you forgot to set it in your haste to get a video finished and only find at editing that your content is unusable.
Leaving a camera on autofocus takes away that problem, no need to think and get it set right every time.
I'll use manual focus for some thing likes the whiteboard, so no risk of focus hunting, but on most other things autofocus (with peaking) is the bomb.