Oak riddle explained

I was compelled to explain what was the original riddle about, because I noticed many of you didn't understand why I didn't accept some of the answers as solution to the riddle. I'm open to the possibility that I was in the wrong, so if you still think I'm in the wrong even after reading this, please explain why in the comments.

How idea for riddle happened:

I needed an oak on top of a pillar for my newest survival building project (if you liked my Shamanic portal hub, this one won't disappoint). I noticed that if I just raise terrain around the oak, I can make oak raise along with raised terrain. I raised the terrain to max, and ended up with an oak on a pillar, I pickaxed the pillar to make it thin:

Oak on a maximally raised terrain pillar

This however wasn't tall enough, for my building project so I decided to dig around the pillar to make the pillar taller. I ended up with taller pillar and moat around it. Not very pretty and I still had limited building options:

Oak on a maximally raised terrain pillar + maximally lowered terrain around pillar

I noticed I have to widen the moat, if I wanted more room for my building project:

Oak on a maximally raised terrain pillar + maximally lowered terrain around pillar + wider moat

It was wide enough, but I didn't like the 90° angle cliffs, so I decided to smooth them out:

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Oak on a maximally raised terrain pillar + maximally lowered terrain around pillar + wider moat across entire mountain

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I thought I did a pretty good job smoothing the terrain (took 10h). Now it was finally ready for my building project, but before that, I wanted to post this picture to see how many people will notice everything that is going on in this picture. So I made the riddle:

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The actual riddle

I gave a hint: "Viking for perspective" to help people figure out that the pillar is double in size.

So to solve the riddle, you had to notice (from easiest to more difficult):

1. That oak can't be planted
2. That you can raise terrain around the oak to make it raise along with the pillar
3. That you can pickaxe the pillar to make it spikey and oak will still stand on top
4. That the pillar oak is standing on, is twice as tall than you usual max raised terrain pillar
5. That in order to have pillar this high I had to dug out the rest of the mountain

I figured that points 1-3 are pretty well know, but points 4-5 would be worthy of making it a riddle. I posted a riddle and got downvoted for not accepting people's answers that touched on first 3 points and didn't notice the points 4-5.