_act_ summed it up well. It's absurd to compare Bitcoin and Ethereum about decentralization.
They sold premined ETH with ICO. Bitcoin never do that.
Technically, it is. Bitcoin never had ICO and there were no premined sales. But there is a nuance. But what about the early miners and investors, now called whales, who mined, bought, or otherwise accumulated a lot of BTC? Unequal distribution among the owners of bitcoin still exists (ever since), which is not entirely correct from the point of view of decentralization.
Although the comparison of ETH and BTC I think is completely redundant, because BTC undoubtedly wins by a huge score against ETH in terms of decentralization. In general, and not only in this.
Vitalik Buterin is a known figure and have the biggest influence over the market, even for other coins. Bitcoin don't have this type of figure.
For any cryptocurrencies that have public representatives of the project, like Vitalik Buterin, they are a weak spot. They can change the direction in the market not only of their project, but of the entire cryptoindustry as a whole with their statements alone. Of course, this is a clear minus for decentralization.
They even roll back and forked the coin. Ethereum isn't even in their original chain, Ethereum Classic is.
With Bitcoin, too, not everything is so simple. What about Bitcoin Cash? It's also a forked coin. At this point, there are similarities between ETH and BTC, right?
Switching from PoW to PoS is a hit about decentralization.
Absolutely.
Ethereum has its benefits, but it's impossible to talk about decentralized ETH anymore.
It was impossible to talk about decentralization ETH initially. Since the inception of the project.