The blockchain and cryptocurrency industry is an industry that is constantly changing and evolving. So it’s hard to give you a binary answer inmy opinion. I honestly love both the projects.
However when I look at it from a larger perspective, I realize that the industry is rapidly changing and the top project maybe something we least expect. I see a lot of development happening in the Web3 ecosystem with respect to Polkadot. I see new projects like Concordium which are exploring new paradigms like Faas( Finality as a Service ) and are backed by years of Academic Research. DeFi is changing the way we know Finance.
If there is one thing we can learn from the industry, its that change is the only constant and BTC is King. It has always been.
Ofcourse Ethereum is very innovative, it is infact one of the most innovative projects out there, but BTC will continue to dominate unless Ethereum brings something so huge that it will lead mass adoption and will be seen a better store of value than BTC. Ethereum was never intended to be a store of value.
For what I know, the competition is getting fierce every day. Right now Ethereum is in the lead, but that could change in the future as other Blockchain platforms take the world by storm. It's all a matter of adapting to the latest technologies in order to stay ahead of the game. With Ethereum constantly delaying its PoS upgrade, its competitors could gain an advantage in mainstream adoption. I don't think Ethereum will overpower Bitcoin anytime soon since it's not meant to be a store of value. Ethereum works better as a complement to the main Bitcoin blockchain than a replacement. Comparing both Bitcoin vs Ethereum is like comparing apples vs oranges.
Needless to say, anything can happen in crypto land. I've seen many prominent projects like Polkadot, Tezos, and Cosmos advancing in development and innovation. If Ethereum fails to scale, you could expect these alternative blockchain networks to take its place anytime soon. But taking down Bitcoin is another story. The premier cryptocurrency has brought Blockchain technology to the world, with a solid foundation built upon it. You can't take down something that started it all. At this point it's practically impossible for Ethereum or any other cryptocurrency to overpower Bitcoin in any way. Ethereum might as well focus on being an alternative blockchain network for smart contracts than a store of value. For different purposes/situations in life, will be the type of cryptocurrency to use in the mainstream world. I'm on Bitcoin's side since no other cryptocurrency matches it in terms of security and decentralization. With ETH switching to PoS soon, it will become less decentralized than Bitcoin. And you and I know, this reduces the odds of ETH overpowering BTC in the future. Just my thoughts