This is just my personal feeling, groundless. If my idea is wrong, please correct it.
I learned about cryptocurrency only last year. I was lucky to know several senior players. I found a preference among my friends. Friends who support bitcoin will despise other coins, and he will scoff at new play items in the market. Friends who support Ethereum are very interested in new projects and will understand or participate in them. Over time, I feel that the friends who support bitcoin are conservatives. He only agrees with bitcoin; The friends who support Ethereum are energetic.
The most important reason for Ethereum's success is that Ethereum's smart contract adopts Turing complete technology, which makes the function of smart contract very powerful, and gives birth to popular application innovations such as ICO, defi, NFT, gamefi, etc.I think bitcoin has not changed and may not need to change. Bitcoin is concerned by the state, and Ethereum is a cryptocurrency that cryptocurrency players must buy.
I'm just a feeling of myself. I don't mean to offend anyone.
You have noticed correctly, that Ethereum is developing all the time (new projects and updates), as opposed to stuck Bitcoin. People who prefer Bitcoin make their choice in favour of safety, as Bitcoin is one of the safest investments in the crypto world. Those who invest in new defies, new projects and altcoins are ready for risks and they are more likely to have a big profit.