Old way still works

I've a freelance work that needs to use WordPress, but I've not developed WordPress for a long time. I need to build a WordPress theme that provides flexibility for the client to change the website content.

I saw there is a Gutenberg block inside a new WordPress panel and it's built on top React and Javascript. Pretty cool.

After one hour, reading the documentation, and I decide not to pursue it. It might take several hours or days to learn and apply it to my freelance work.
I decided to use the old way. Digging back my old repository and skim all the WordPress theme I've ever made. I'm using a plugin of Advanced Custom Field + Custom Post type UI to provide the UI for the client to manage it.

It works as expected.