This stuff has a back and forth to it, but I really doubt people are documenting less stuff today than they did in say the 1920’s. Workers have less to high over these decisions than the people making them so there is often low level smoking guns.

And sure, several Secretaries of State used private e-mail severs, but there was also significant backlash over the practice. Again I doubt things are less documented today than before computers became the norm.