If you are a WordPress multisite administrator of students or teachers blogs, you may want to make the block editor simpler since you know they are in a learning curve to master the modern editor.
Restricting access to only three or four blocks (like Paragraph, Heading, Image, and Table), which are used to compose a jounal or report will certainly reduce the complexity.
To achieve that goal, you can login as a network administrator to the main site’s admin area. Then go to Plugins > Add New > search for “Gutenberg Block Manager” plugin. Click the Install button on the Gutenberg Block Manager plugin that is authored by Darren Cooney.
Then you will want to enable it either on all sub-sites at once or the selected ones only from the individual admin area of each sub-site.
Then go to Settings > Block Manager from admin area of a site you wish to apply blocks restriction.
The screen will take you to the list of blocks grouped by category along with the on/off toggle buttons. You can globally switch on/off for all blocks at once under a specific category or pick block by block.
Do you know a simpler way than this? Let me know in the comment.