ERC20 standard on github https://github.com/ethereum/eips/issues/20
This guy has good tutorials: https://www.youtube.com/channel/UCaWes1eWQ9TbzA695gl_PtA
First 5 mins is me going through the smart contract, after that is example usage and talk about state of Ethereum , how I see it.
But still, even if ethereum finds a few use cases that actively use gas on the network, the price of Ether will be worth something. How much? No fcking clue.
As far as Hedera, I don't know yet. It's a private not a public ledger, so I don't imagine it will be popular among crypto people.