Block Editor has forever changed the way we can use WordPress. The idea that we can create blocks of content and arrange them in a way similar to components allows great flexibility in the way we create content and provides an opportunity to develop new types of modular content. The concept is not new and exists on more complex and serious CMS systems like Drupal for years but it is certainly a welcome addition to WordPress that is used often.
Blocks allow for variations, they can be used multiple times and in different patterns giving us a great tool for designing layouts directly in the editor.
Where does all this lead? Namely, WordPress has plans to enable blocks for targeted global elements - menus, headers, footers, etc. - to establish the ability to edit full web pages or FSE (full-site editing) directly in WordPress without the use of plugins.
For me, this is a welcome innovation, but it also means that theme developers will have less work to do, and it also marks the decline or evolution of certain popular technologies that you can lease today with a lifetime license.
All of the above is already available and can be tested by installing WordPress 5.6+ with TT1 Blocks and Gutenberg plugin.
The development in the block editor is a great mental help from the previous WordPress experience in a positive direction, but currently, it lacks documentation that will be resolved in time. Everything is still in active development and with each new WordPress release, we are gradually approaching the FSE goal, ability to edit full web pages directly in the editor.