Im not a dev, Im actually from the design side of things, similar timeline as yours, different direction, but same lifetime passion you have, but my story is irrelevant.
My initial thought of dark mode was due to you saying you got the agent to mostly build the website out, with you making tweaks. My experience with most “just let them build” scenarios, the agent inevitably asks or prompts, “How about Dark Mode”, hence my question. You even say it again above: But credit must go to Replit’s design mode.
However:, Fair play, it’s your masterpiece, you get to hang it on your wall. But it’s not only for. your wall, it’s for the public to come and read and engage with. Your analogy of painters and directors is, that they dont care if the people dont like their work, it’s their masterpiece. Your website, needs to draw people in, you need everyone to engage with it, Not everyone likes Scorsese, but im sure he would have wanted more people to see his work, than what have.
I have a day job, so I work outside at night, in very low light conditions, next to my pool, everything in dark mode, screens on night mode. I clicked your site, I was blinded for a few seconds at 11pm. 
Thats not to say the information or design was wrong, I just I had to wait a few seconds before I could read it. 
To be honest, the last project I have literally finished has explicitly : NO DARK MODE
And it a dashboard/presentation scientific website, the same ones you said, could benefit from dark mode.
So no, it’s not me “wannabe dev” going, “bro, you forgot dark mode”
And, I would never take what you said seriously, this is a forum for discussion, if I can’t handle criticism, that would be a bigger problem, life’s too short!
