Gutenberg is the new post editor for WordPress websites released in V5, it totally replaced the old editing experience with a brand new, drag and drop editor.
There can be a couple of reasons for this and the most obvious is the feeling among developers is the new editor was forced on them, some developers felt the old editor was perfect and didn't need replacing. Gutenberg also uses react, which means a lot of WordPress developers needed to learn a whole new code base to customise the new editor.
Gutenberg was created to make editing your WordPress content easier, the old editor was based on TinyMCE which had a limited editing experience for users. WordPress competitors such as Medium and Wix had much better editing experiences, WordPress was lagging behind massively.
As a developer, it was scary to learn a new language, a new editor and having to teach my clients a whole new editing experience but overall the editor has massively improved my clients editing experience with WP, they now have an easy to use editor which has it's faults but overall they enjoy using Gutenberg far more than the old editor. They rely on me less to help them update their website content and they have much more control on how their content looks.
Gutenberg will continue to grow, the editing experience will get better and more users will begin to use it. More developers will get on board with it to expand it's functionality and ultimately both users and developers will wonder why it took so long for WP to replace the old editor.
Have you used Gutenberg? Did you enjoy the experience? What would you like to see from Gutenberg in the near future?