Personally, I think that if Ethereum replaces Bitcoin, it will be something very interesting and super-large-scale event. But this will not happen since Bitcoin Ethereum is now in its place and is developing promisingly for the benefit of society. And I think that soon the most important coins will surprise us with their new discoveries.
every time ETH has progressed in development, BTC will also increase progress in development. so I think ETH will remain under BTC. we can also see that there are still many people who invest in BTC so that BTC will remain strong and become number one.