Some people misled people that ethereum one day will increase above bitcoin in marketcap. But they forgot that there are ethereum competitors. As usual, people will leave the old altcoins and move to new altcoins. That is what that happened to ethereum. Ethereum still tried as it did not get really dumped but it is not a store of value just like the other coins.
Ethereum is controlled by a community of developers, it's not a decentralised platform like Bitcoin. So there can't be one-on-one comparison between these two platforms. Ethereum may be scalable but Bitcoin has no match in security and decentralisation.
Moreover there is overwhelming supply of Ethereum coins in the market i.e around 120 million Ethereum coins are in circulation. Ethereum shifted to PoS in Sep 2022 and since then 1,947,607.01 Ethereums have been burned while 1,947,757.18 new Ethereums have been added to circulation. So there is net increase of 150 Ethereums in the marekt while PoS was adopted to decrease the supply of Ethereum coins. With so many coins in the market, its still a blessing for Ethereum that it has a price over 2500$..
https://www.binance.com/en/square/post/02-05-2025-ethereum-supply-surpasses-pre-merge-levels-19889163958794