Canadian programmer Vitalik Buterin has recognized Bitcoin’s advantage over Ethereum in such aspects as censorship resistance and decentralization.
Buterin believes that this is the case due to less code complexity, lower rate of protocol change, higher full node count, and less dependence on RPCs (remote procedure calls).
Bitcoin’s protocol is simpler, which makes it easier it easier to audit and harder to introduce bugs. At the same time, Ethereum’s smart contract capabilities add a lot of complexity, increasing risk.
The Bitcoin community is also extremely conservative when it comes to implementing new changes, which enhances predictability and trust in the long term.
Finally, more people run full Bitcoin nodes, which means that the network has a higher degree of censorship resistance. These nodes also do not rely as much on external services, which is not the case for Ethereum applications since they are often dependent on providers of the likes of Infura.