Hmm. Great post, not so sure about the title.
I'd say (and I think this is actually compatible with the article itself, if not the title) that a better rule is to write about things that you've only just started understanding. The OP is, I think, correct that you might write a better introduction than an expert for whom it's all obvious if you've just been through the struggle of learning it, because the journey is fresh in your mind.
The risk of sounding more knowledgeable than you actually are is a real problem, though, and I'm glad he mentions it. It's really tricky to strike the right balance between making it clear that the topic is new to you, and hedging so much that you sound like ChatGPT on a bad day.