There is no point in talking about 2017, because now post coins are no longer the same as 2017, every year the conditions are different, if in 2017 participating in the airdrop project alone can be profitable.
It is about the technology, not profits. And no one said anything about an airdrop
Yes, cold staking is now working on the Callisto network. You can learn more about this at the following link:
https://callisto.network/cold-staking/But I haven’t yet heard about the PoS system without using a private key.
Interesting, thanks for sharing. Not the cold staking I was thinking of tho, the Callisto method would be detrimental to network stability. I wonder if they gave it a new name, like stake by proxy or something.