the historical reason for staggering are the metal arms on mechanical typewriters, which obviously does not make any sense nowadays, but unfortunately the design stuck, as did the qwerty layout.

non-staggered keyboards, such as the kinesis advantage, better match the shape of the hand, sometimes even with vertical "staggering" instead of horizontal.

additionally, the thumbs are the strongest fingers but are only supposed to hit the (huge) space bar. this is the problem that alternative physical layouts like the ergodox and the kinesis advantage try to address.

also, split keyboards allow you to use wrist and arm angles that match your body instead of the keyboard.

different letter layouts like colemak (good, especially modern computers) and dvorak (also good, but designed in the pre-computer era) significantly reduce finger travel and improve on finger and hand alteration. for me personally, colemak works great to prevent strain.