Bitcoin is the gateway into crypto. Check the marketcap, and all the pairs are tied to BTC on most major exchanges. It's also the most secure and has the largest community. It's use case is different than Ethereum's.
Ethereum's mining fees exceed Bitcoin's:
That would mean it has better long-term security prospects than Bitcoin, as security is proportional the revenue earned by validators.
That's why I said that Ethereum's long-term security prospects are better. Its mining fees have exceeded Bitcoin's and with the multi-pronged efforts to further scale Ethereum - that are vastly more promising than Bitcoin's - there is a high likelihood of these fees further increasing their gap with Bitcoin's.