My opinion is, as it was in 2020, that defining masonry as part of grid would be a mistake. This separation respects the unique features of each layout.
Good defaults in CSS make it easier to teach and understand layout methods. They guide users to comprehend what each method is inherently designed to do.
The defaults when using display: flex or display: grid set a useful starting point, allowing for straightforward modifications instead of overwhelming new learners.
Flexbox’s default behavior of aligning items in a row provides a foundational understanding that simplifies teaching, making complex layouts more digestible.
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