When I first heard about this anime I thought, "Oh. I get it. It's one of those animes that teaches you about culture. I'm not interested." I put it off for years. But every once in a while ppl I respected would talk about their favorite animes and Golden Kamuy was always in the top 3. I didn't get it, but I couldn't say a word bc I never watched it. After watching it, I get it. There's no way to summarize Golden Kamuy. If you tried you'd miss out on so many details that it would make it an insult.

I tried to summarize it and here's how it sounded:

It's about aging and how much of you is left over time, what defines strength, manipulation (is it a good thing or a bad thing? Like Odyssius in the Iliad and the Odyssey was manipulative, but it was all to help his side. Was he a bad person for this? And if so, why did the Greeks hold him in such high regard?), deception, betrayal, nature and our place in it, trauma, death, how best to live your last moments, the thrill of battle, secret identities, plot twists, how native populations are often forgotten as well as their culture bc they're killed off without regard and their surviving children forget things like their language. It's also about violence and the question of when is it justified.

That's the best I could do and it's not remotely accurate, bc it's about much more than that.

Here's how one person summarized it:

The reason it's not more popular is bc:

It's not an isekai
It's not set in a bloody school
It's not a shonen

That isn't why you should watch the show, though. Isekai and regression arcs are out of control but the public clamors for more. And shows like this, Undead Girl Murder Face, and Under Ninja are forgotten before they stop airing. Even Hikari No Ou was lit and no one ever talks about that show despite the hype it got before it aired.