I only make a small dent from my self-published book (Deployment from Scratch), but at least I get to keep it. If I write a story one day, I would love to do it

I only make a small dent from my self-published book (Deployment from Scratch), but at least I get to keep it. If I write a story one day, I would love to do it with a good publisher and be in the book stores, but for technical content I'll stick to self-publishing (not that I have any energy left to do more titles hah). I also see some people distributing self-published physical books themselves. Would love to know the hows and economy of it.