It’s been under development since 2019. The concept arose from JetEngine. The basic idea was, hey we like what JetEngine is doing in creating a suite of tools that work together as building blocks. However, we kind of miss our old friend, Advanced Custom Fields. In fact JetEngine in addition to having it’s own meta field options, did also provide ACF support.
The interest in building a full suite of tools around ACF wasn’t just about fields. One of the most promising and exciting developments in ACF aligns really well with the integration recently of Site Editor, the Gutenberg way of creating and overriding page and post templates as well as building out site headers and footers. ACF Blocks are a feature that normally only developers can access. And as we see other plugins popup to offer various block building options, still few provide the simplicity and reliability already baked into ACF with it’s convenient dynamic block registration features.