I want Babel to continue to exist, even if it steered by an engineer who is not "the best in the world", if we take your assertion at face value (higher salary = better engineer).
Since we're taking Silicon Valley metrics seriously, I will posit that there is a least 1 Eastern European engineer who's better (based on HackerRank/leetcode/CodeJam stats), and is willing to accept a lower salary. So Babel might be better served recruiting there.