WordPress 6.0 introduced simplified pattern registration to address problems with the manual register_block_pattern() approach that was complex and inefficient.
The old system required function calls with large HTML blocks, manual file management, and fired on every request (frontend and backend) even though patterns are only needed in the admin.
These inefficiencies led to complex registration systems like Twenty Twenty-Two’s loop-based approach that processed pattern files through arrays and function calls.
The autoregistration system eliminates this complexity while improving performance by only registering patterns in admin contexts where they’re actually needed.