@b0rk
That's one example.

In general, distributions are points where standardisation between various bits of the Linux ecosystem actually matters.

For instance, you can rely on your system following the FHS, not because upstream developers care, but because distributions do. Reproducible builds are another example of things that were pushed by distributions.
@bookwar

@b0rk
These improvements are usually pushed back upstream, because distributions don't want to have to maintain things like that in a branch long term. But these are shared interests, and for those, distributions are the ideal point to implement them.
@bookwar

@b0rk
To demonstrate how far this goes: Debian's policy document (https://www.debian.org/doc/debian-policy) explains the technical requirements of a Debian package. The first 5 chapters explain the technical details of the packaging system; the next 2 explain how the packaging-specific bits should act. The 5 remaining chapters explain how the packaged software should behave.
@bookwar

@b0rk
In other words, almost half the standard is about standards for upstream, rather than for the packaging-specific bits.

That comparison is a bit skewed though, because a lot of the last part of the document includes other standards, such as FHS or XDG, by reference.
@bookwar