Have you written a book or collaborated to publish a book?

I have started with Amazon KDP to write a book or two, I was wondering if anyone else had tried this?

I’ve been writing since I was very young, started with poetry, then attempted to write a romance novel in my early 20s, but life got in the way, and I gave up. I put together a children’s book many years ago but never found a publisher. Now I am working on a self-help book. Now, with Amazon KDP, I heard it is much easier to be a freelance writer and actually publish it for the community to read. I was wondering if anyone else had tried their hand at writing or collaborating and publishing a book or two.