Headless CMS: why they're all so full of features?

Hi! Doing regular research to improve the results of BuildGrowth I was looking for a solution to change the content of my website dynamically. I thought: easy, headless cms.

Then I searched for one that would be easy to set up and had a clean interface. I just couldn't find one.

Every single Headless CMS out there is so full of features and the setup takes more than 1 hour. But why?

What I need was just a CMS with two options: pages and posts (inside the pages). Think of Ghost, but cheaper and with fewer features.

Anyone knows a good almost "drop-in" solution to this? A solution where I don't spend more than 30 minutes to set up the thing. I want to create the content, request it via API, and then show it in the frontend. Simple as that.