As I understand it, the protocol will be used by ERC20. But, now newer and more compatible protocols are being used. ERC223 for example. Faster and safer.
yes indeed I think there are currently many projects that use Erc223 as their protocol. But sometimes there are still many projects that use Erc20. all because there must be a reason even though ERC223 has more advantages than ERC20.
This is because the developers are too lazy to study the ERC223 protocol, and they use old knowledge. But, since the project has not yet been created, it is necessary to switch to new technologies. Otherwise, the project has not yet been created, but is already outdated technologically.