Comment by kbart

"What if the maintainer never marks the library as deprecated? What if they're just hit by a bus?"

There are a lot of "if's" and many things might go wrong -- there's almost never 100% guarantee, but every mean that makes end product more reliable is a good idea.

"I feel like if you have so many direct dependencies that you can't keep tabs on them, you simply have too many."

Such number of dependencies is common when building custom Kernel/OS + application. Also, I've never mentioned direct dependencies, some are just tools to build tools. It wasn't event that big of a project -- a relatively small (~150 Mb) custom OS with Qt application for an embedded device.