As the article mentioned Einstein as a teacher, I think it’s worth asking about his writing too. I think his actual papers are very good at explaining the theor

As the article mentioned Einstein as a teacher, I think it’s worth asking about his writing too. I think his actual papers are very good at explaining the theory and indeed better than many textbooks. I think a good way to start learning eg special relativity is to get a copy (available online) of Einstein’s first paper on special relativity and read it. The paper has to explain it for people who have never really seen such a thing before. Obviously a certain level of mathematical ability is required to understand the paper and maybe this is more than required by a modern textbook. A modern textbook may also explain things in a different way with eg 4-vectors and lots of spacetime diagrams.