30 minutes per month for 3 posts. This leaves you 10 minutes each to write the content, create images and graphs for each post, adapt it for each platform and post it there.

That doesn’t sound like 30 min work for me! I have no idea how this could be done in this timeframe.

It’s all about the idea. Even if the guy is not following through with his plan, a couple of the viewers might do so, marking it a success.