Hello Arwel ,
Thanks for writing in.
The native coin in the only one in active development. The ERC-20 coin is a legacy token from before IoTeX had it’s own blockchain. The IoTeX mainnet launched in 2019, but the project itself started on blockchain Ethereum. Ever since then IoTeX supports the efforts to swap as many as possible erc-20 in existence to native IOTX tokens.
We are late with this action, partially due to Coinbase’s lack of interest in working with us on token swaps. You can see the official token swap thread here Official IoTeX Token Swap Thread
Binance, for example, as seen here Binance Will Support the IOTX Mainnet Token Swap | Binance worked with IoTeX to perform seemless native swaps from erc-20 tokens to native IOTX tokens and burns the erc-20 tokens upon receiving them and converting them to native.
Best Regards,
Jeremi Rynkiewicz