Admittedly, I have purchased deals. Not every single one but certainly when there is a tome with in it. (Because yeah, Tomes are my bane as I’ve purchased more tomes than I have had drops…excluding quests). Atlantis bonus chests contributed as well.
However, 2 months in I was pulled up to fighting 10* (leader saw that I was really eager and motivated to progress) and have been fighting 12* for the last 5 months. Drops were generous at lower player level than they have been after level 30 (confirmation bias…perhaps).
Finally, I open at least 5-7 chests daily, constantly skipping that cooling period and forcing an elemental to appear on a weekly basis (though, elemental chests have been quite horrid for the last 5 or so).