They say that Nephi taking the plates from Laban was when Nephi started acting as a sovereign.  Not just because he ultimately took charge of the mission.  Because he asserted the rights of life and death that only a sovereign could assert.

It was obviously a life-changing event for Nephi, one of those events that mark eras.  That is why the sword of Laban survived all the way through Nephite history as royal regalia (see  more here).

But the brass plates also survived, and so did the groups of plates that became the Book of Mormon.

It was right after the Laban episode that Nephi started keeping his own records.  Made a big point of it.  He had very good reasons for keeping the records.  One was that it underlined his authority.  The Laban episode was a miraculous and defining validation of Lehi’s visions and patriarchal authority, and Nephi’s faith and divinely-conferred leadership–both of which had been challenged during the episode.  So keeping records, among other things, affirmed the right to rule.

Nephite rulers continued to be recordkeepers down the end.

Keep a record for yourself and your family.  It is your claim that you are yours.  It is your claim that they are yours.