Every pinned dependecy is a security vulnerability, sooner or later.
For example, I'd rather install React Router for routing in a React app instead of writing my own routing library. I guess some people will reply "grrr React, just use static HTML bro". Okay cool.
How will you know if/when that happens?
Are you subscribed to the development channels of all your dependencies? Do you examine every one of their commits for security fixes?