Bitcoin still stands out as the main cryptocurrency, but it doesn't mean it will be the best in near future. I believe that with the development of this space there might be some decent crypto. As for now, Bitcoin is dominating but the BTC market dominance is decreasing every year and I think we will come to the point when altcoins will be on their own value not correlated with Bitcoin
and also agree that there is alot of good altcoins in the market, they doing great for example XRP, stellar, cardano
ETH coin could be down grade in future if more developments not implement.
for now eth competitor is EOS, XRP, cardano, lets see what will happens in future. eth having an advantage and that is eth is the fisrt decentralized crypto