Hi Shaun wallace, SaaS and other paid services are perfectly fine to me, even on their free plan. The CMSs in this article also have (or soon to have) cloud versions. For a side project, self-host is better a way to learn more skills, so it is my choice.
That said, I did go over Contentful, Prismic, Storyblok, and GraphCMS in my How To Choose The Best Headless CMS For Your Blogfolio? article and they generally lack features compared to solutions presented in this article.
I hope this answer your question.