The traditional publishing route: agent, publisher, advance, two-year timeline to publication: still exists, and for some creators it is the right path. The advance provides financial certainty during a period of deep creative work, and the publisher's distribution network can put a book on shelves and in catalogues that self-publishing cannot access. But the terms of that relationship are rarely as favourable as they look from the outside.
A standard trade publishing deal typically offers royalties of 10 to 15 percent on print, lower on ebooks, and an advance that must be earned back before royalties begin. The author owns the intellectual property but the publisher controls the cover, the title (often), the pricing, the release timing, and the marketing budget. For a creator with an existing audience of any meaningful size, the economics of this arrangement rarely make sense.
Self-publishing through a platform like Amazon KDP or a combination of print-on-demand and direct sales produces royalties of 60 to 70 percent on digital and 40 to 50 percent on print. The creator controls every aspect of the product and publication timeline. The distribution is narrower, but a creator who can drive their existing audience to a sales page does not need broad distribution in the traditional sense.
The credibility gap between traditionally and self-published books has narrowed significantly. A well-designed, well-written, well-distributed self-published book is indistinguishable in most contexts from one with a publisher's name on the spine. What matters is the quality of the content and the professional execution of the product: both of which are within the creator's control.