I always thought that the biggest benefit of normalization was deduplicating mutable values so you only need to update values in one place and everything stays nicely in sync.

Classic example being something like a “users” table that tracks account id, display name (mutable), and profile picture (mutable). And then a “posts” table that has post id, account id, and message text. This allows you to change the display name/picture in one place and it can be used across all posts