Are you sure that any coin could be the next ETH? Its relaible old project with big army of supporters (including devs) and why something should replace it? I dont think that we will see next ETH in this decade
I'm not sure that in this decade there will be a new coin that will become the next ETH, because building a really strong coin platform like ETH is very difficult and takes a long time to complete, so who thinks there will be ETH coins next I think he is very wrong.