I wish I could win the lottery too but apparently the gacha system works by everyone drawing from the same pool and every 200 draws a 6 star is added so you'll only ever get one (two if the 6 star cards overlap across the 200 draws) 6-star from a draw.
At least that's what this video is trying to say.
https://youtu.be/Zlg9Mkj0KEE
Wonder if it still holds true for the nutaku version?
- - - Updated - - -
Meant to post this video actually, but they're both related
https://youtu.be/vCb1FP_MCl8