What really changes when you decide to publish a book online?

[aimeemoore]

I've been seriously preparing to publish a book after years of writing privately and honestly, the technical side feels manageable but the strategic side feels completely foreign. So I'm asking authors who've genuinely been through it which platform did you choose to publish a book online, and what did that decision teach you about visibility, royalties, and reader reach? Where did things get unexpectedly complicated? What would you honestly do differently? Real experiences only, please.