I really meant within the right context, which would be western folks in tech talking about notable people in the industry, and likely have mentioned Google at some point in the conversation. Sergey isn't a common name among the notable in western tech.

Elon is even more unique of a name to western ears, so I was just pointing out that another (yet less unique) name also gets the first-name treatment.

For more examples, I'd say Satya Nadella also gets 50/50 first/last name treatment in casual conversation.