[overshard]

I just skimmed this article since it does seem like a bias post from a Headless CMS provider however almost all transitional CMSs that you can use/build also provide the features of a Headless CMS. WordPress has a REST API built in, Wagtail has an API built in via django-rest-framework. I'm sure if I looked almost every other CMS has solutions for this too.

The build vs buy decision is still straight forward. Does the headless CMS solution I'm buying provide all of the features my project will need with room to grow? Yes? Cool, why bother building it. No? Looks like I'm building my own on a "reliable framework" (tm) already used by hundreds of thousands of sites.