It's more that the risk of 50 gems doesn't seem to be worth the reward compared to what else I could use gems on. I'd rather get the guaranteed value of manyus to level my existing good characters along with seeds for the normal draws. Also the normal 10 draw I just did:
I know this isn't the typical normal 10 draw, but I've now gotten as many 4 stars from the normal gacha as the premium one. I'm also seeing people say that the premium draw gets improved or something in future events, so (as a free player) I'm saving my gems for then if possible.