By 2023, I think ETH will still cost more than NEO. In addition, NEO may even leave the market, leaving room for a new Chinese project with a smaller capitalization.
What is clear is that no one knows for sure what will happen in the next 5 years with the two coins. If we look at the current market potential and capitalization, it is likely that ethereum will continue to survive and increase its price higher and have a larger market capitalization than now.
it's possible that Neo will replace Ethereum in the next 5 years by bringing a better concept than ethereum for faster transaction costs, we just wait for the time that will happen again both for the development team and investor interest.