Fedora opens up to bundling

Gentoo does strongly discourage bundled packages but it's usually not something that would keep a package out of the tree. There's a couple examples where we compromised and let the user make the decision themselves of whether to use the bundled code or the system library, the most notable being Firefox where there are such options for system cairo, icu, jpeg, vpx, and sqlite.

I think there's one advantage of distro unbundling that software developers overlook. By building your package against system libraries we often find bugs and incompatibilities in those libraries early. When the time does come for you to update your bundled code to a newer version those bugs, that would have cost you valuable time and manpower to debug, test, and fix have already been resolved upstream. That means fewer local patches for you to carry around and less divergence from the upstream code, making it easier to backport any future bug fixes, etc. etc. Just as often we find bugs or incompatibilities in your package and can also get them fixed early, or at least make you aware of them.