Maybe Evan is a liability, but he might also be the reason why VueJS is popular and valued in the first place.
It also seems pretty strange to me to count VSCode and GitLab in there, because those are worked on by companies with teams behind them that get paid and which will have constant churn.
If you took VueJS, and had a team at Microsoft take it over from Evan, it too would live on. So I don't know that your explanation for the "risk" here has anything to do with "very high impact" and more to do with a project being maintained by a community of backers, on people's free time, and a project maintained by a company that hires developers to work on it full time.