Pre-sale and pre-mine are huge factors, imho
Discussion
Not to mention those who hold the most eth, now under pos, get to vote their proposals through.
& they are also PoS, so technically they control everything š¤·āāļø
Yes, that power comes from having a huge pre-mine
Iām no securities lawyer, but the pre-sale seems enough for me to qualify it as a security because it checks all all boxes. 
The ethereum foundation already had control tbf, which was p apparent when they forked after the DAO hack.