Hello,
I have $306 Tether in my MetaMask wallet and when I want to change it to another coin or token or send it to another wallet, then it need 0.07166 Ethereum!!! When I want to swap it to Ethereum, it needed Ethereum too 
If anything need Ethereum, then why MetaMask support other coins and tokens?
Thank you.
Hi @hack3rcon thanks for reaching out!
The Ethereum network requires gas to execute transactions. When you send tokens, interact with a contract, send ETH, or do anything else on the blockchain, you must pay for that computation. That payment is calculated in gas, and gas is always paid in ETH.
You are paying for the computation, regardless of whether your transaction succeeds or fails. Even if it fails, the miners must validate and execute your transaction, which takes computational power. You must pay for that computation, just like you would pay for a successful transaction.
Thank you.
Any idea for use my Tethers?