Your point is well taken, if not a little snarky, but it doesn't give you any more or less room to reframe, you'll have the same exact amount of resolution.
I've personally never found myself in a position where I wished I could zoom in by 2 in order to see what I want to frame later so I wasn't able to relate to it but if it helps someone then I guess it's a valid reason. Someone else pointed out that they want it for FPV and you would see that my answer was "fair enough, I get your point".
Haven't you edited aerial videos and seen things you didn't see while flying? The 2X zoom could have helped. If you had zoomed in you could have seen it and spent more time featuring that POI that you missed.
Here are some examples of the utility of the 2X zoom in scenarios that post edit zoom and crop will not benefit.
1. Inspecting antenna towers for birds nests, rats nests or any obvious wind or storm damage. Close up zoom view
while you're flying helps to know where to spend more time inspecting with better angles for clarity.
2. Looking for animals on the ground, a close up real time view helps to see through the bushes better to locate animals hiding.
3. Staying a good distance away from people you want to record to not be rude, but you need to find the person you're looking to feature in the video. Safer flight too.
4. Recording rock climbers, finding a specific climber on the side of a mountain that you're looking for, zoom helps while not getting too close.
5. When recording a car zooming by on the highway, zooming in to identify the car you're looking to capture before it gets to you, so you track the right car as it goes by.
6. Inspecting bridges for structural flaws to take photos of the point of interest, seeing the problem areas during flight to spend more time taking photos of those problems.
7. Search and rescue. Time can be of the essence to find the lost person, there's no time to review in post edit. You would need a separate crew to review video while you're flying to cover more ground if you want to zoom during post edit.
What you can see while flying influences the flight agenda, the closer you see the more detail you see. The more you see, the more interesting the video can be. Seeing something in post that you didn't see while flying cannot be reshot. If you miss something you didn't see while flying, you've simply missed the opportunity to optimize the shot, spending more time, looking for a better angle. You can't turn back time and capture something you wish you would had seen during the flight.
Besides the utility of 2X zoom, I find it cumbersome to shoot in 4K all the time. I realize I lose the opportunity to post edit zoom and crop, however that's not as important as the SD card space, and 4K takes more time to edit. I just don't need 4K for my purposes, today. It works for me, today, maybe not tomorrow.