String spacing ... again....while building a 6 string bass

Hello all,
I am new here, posting anyway. Been reading on and off for years.
I am building a 6 string as the title states.
I have been reading and watching videos about spacing at the nut. Most seem to space the strings with even spacing between the strings and not spaced center to center. I haven't really paid any attention to this over the years over multiple basses. But that aside. This is leading to part two of my thoughts.
If the majority of basses are spaced measuring between the strings and not on centers. Why is the spacing at the bridge an equal distance from center of string to center of string?
Just my Friday night thought process.

 

Yes electric. My apologies. New here.... If a moderator wants to move or delete this thread/ question. Please do so.