There is nothing like Satyug ( an epoch when everyone was nice and pious ) or Kaliyug ( where corrupted minds are dominant – meaning now ).
This is how scriptures influence our thinking ( if there are scriptures that say that ).
If in the past there was Satyug, why so many great souls were born?
Supposedly, great souls are born to bring others on the right track.
That means there were lots of crooked people who needed to be corrected.
Then would that be a Satyug or a Kaliyug?
If great preachers existed in Satyug, there must be a lot of people who needed to be preached to.
If there was Raam, there was Ravan, too.
If there were Pandavas, there were Kauravas too.
I would not get swayed away by such statements.