And why will they promote? It is already popular because it's the same as dollar and we know what dollar is right? But the only difference is that tether is digital. Unlike the dollar, bitcoin was still new to many despite of running for some years.
Is it because there is no money to be made in Tether?
No that's not true. You can make money in tether via staking, lending and there might be other more than this which I forgot or I didn't know yet.
Isn't the whole idea of Bitcoin to have a decentralized network that is useful and fair? Isn't that Tether?
1:1 seems fairer than 1:20,000 ...
Yes you're right, the idea of btc is for the people to experience decentralization in terms of money/currency. Tether on the other hand is also useful because we can use it for payment or sending money and also it can be used for trading cryptos to prevent them from fluctuating but on the fair part I think no it isn't really that fair.