Ethereum co-founder Vitalik Buterin has a history of publicly commenting on different cryptocurrencies, including both Bitcoin and XRP. However, there is no reliable record of Vitalik stating that XRP is better than Bitcoin. In fact, his views on XRP have generally been critical, especially in the context of debates about decentralization and the structure of different cryptocurrency projects.
In December 2020, Vitalik made explicit criticisms of XRP and Ripple, the company that developed it. This came after Ripple, in a document submitted to the SEC (US Securities and Exchange Commission), tried to argue that both Bitcoin and Ethereum were majority controlled by Chinese interests, insinuating a centralization in these two projects to defend XRP from accusations of being an unregistered security.
Vitalik responded on Twitter saying: "They are calling Bitcoin and Ethereum 'controlled by China' because XRP is currently being classified as a security by US authorities, and they are desperate to be perceived as 'decentralized'. But not only is XRP completely centralized, it is also a project created by a company, with security that is still under the control of the company."
These statements make it clear that Vitalik Buterin views XRP as more centralized compared to Bitcoin and Ethereum, which contradicts the idea that he would consider XRP superior to Bitcoin.
Therefore, any claim that Vitalik believes XRP is better than Bitcoin is not supported by his public statements. On the contrary, Vitalik has historically advocated decentralization as a crucial feature of cryptocurrencies, something he sees as more present in Bitcoin and Ethereum than in XRP.
If you have come across this claim somewhere, it may be the result of misinterpretation or misinformation. It is always important to check with reliable and official sources before accepting such statements.