Mythics not increasing based on higher tier

I notice that on t4. Ancestral do not drop nearly as much as they do on t3. Plus mythics drop rate is lower on t4 then t3, and this has been the same issue as last season.

how many mythics did you find so far to make that claim? ^^

zero running masses of t4 bosses. I did find far more ancestral items on t3 then I do on t4.

Anyway, this is no bug…
It’s how the dev’s want it to be…

If that is WAI, then why does moving to the next tier state that it increases chances?