I hope you get more out of it than I did. I don't recall which of Seneca's work I read several years ago, but to me it was ... meh?

Some of the stuff I strongly agreed with, but I didn't derive value because I already had the mindset. Other stuff I disagreed with, and the book didn't really convince me. Then there was the stuff in between.

Overall, it felt like something you or I could have written - I didn't see something insightful that enlightened me.

Not to take away from your essay, which I thoroughly agree with :-)