P.S. I invested 0.01BTC in Tether USDT staking, it is something complete different, I always can exchange Tether USDT instantly to Bitcoin, ETH, Stelar, EOS, Ripple, Doge, TRON, Monero etc. PM for the link, if interested.
Here is where we draw the link
The quoted part makes you sound like a complete scammer. Why would anyone PM you for a link. Why don't you post the link here, and we all see it?
Also, the idea of staking is messed up. It's just a huge Ponzi scheme.
He is obviously trying to push his referral link to people, and since it's against the bitcointalk rules to post those, so OP decided to go this way.
But what you said about staking, i can see how staking usdt is unsustainable, but when staking is about securing the chain, it really doesn't differ from PoW in a way it would be more any more ponzi. And word Ponzi doesn't really apply this any more then trading anyhting would be a ponzi.