~snip~
I don't think all this you have listed above are for free, because nothing comes free in life both the cloud mining and advertising airdrop faucet you listed requires one form AF work or the other before the coin are given to you and in most cases their are time consuming and you know time is also money. So I don't think bitcoin and all the other altcoin are given for free you pay for it one way or the other.
I think OP is referring literally for Free,means no literal Money involved,but yes time is also a money but in this case it was different from your view and from OP
But why did Signature of bounty campaigns wasnt on the list?Those are also free even though we are hired as participants yet we are not investing money to earn